image PNG : /home/_math/_exercice/d0/893/metapost/05_1.png
E.11524
A
driver
drives
at
a
constant
speed
of
111
km
=
h
for
42
min
.
What
distance
did
they
travel?
E.11525
A
cyclist
rides
at
a
constant
speed
of
19
;
5
km
=
h
on
a
route
of
35
;
1
km
.
How
long
did
the
trip
take?
E.11526
A
driver
travels
a
distance
of
141
;
9
km
.
He
leaves
at
9
h
47
and
arrives
at
11
h
26
.
Determine
the
average
speed
in
km
=
h
for
this
journey.
E.11527
A
cyclist
sets
off
at
14
h
22
on
a
journey
of
75
;
4
km
and
rides
at
a
speed
of
39
km
=
h
.
What
time
will
he
finish
his
journey?
3.
Reminders:
proportionality
and
percentage
E.874
Emilie
and
Antoine
each
make
a
chocolate
cake.
Antoine
uses
100g
chocolate,
20g
flour
and
30g
milk
pow-der.
Emilie
uses
220g
chocolate,
45g
flour
and
58g
powdered
milk
Calculate
for
the
two
cakes,
the
percentage
of
chocolate
they
contain
respectively.
Of
Emilie
and
Antoine,
who
has
the
cake
richer
in
chocolate?
E.9236
According
to
the
2000
census,
Mex-ico
would
have
102
million
people,
of
whom
34
million
would
be
under
the
age
of
14
.
What
percentage
does
this
age
group
represent
of
the
total
population?
(value
defaulted
to
the
unit)
E.898
1
What
sums
are
3.85
%
of
150
000
e
,
378
000
e
,
500
000
e
,
then
1
000
000
e
?
2
What
percentage,
rounded
to
the
nearest
hundredth,
of
500
000
e
représente
14
553
e
?
3
What
percentage,
rounded
to
the
nearest
hundredth,
of
1
000
000
e
représente
14
553
e
?
E.887
A
miniature
globe
has
a
circumference
of
40
cm
,
while
the
circumference
of
the
earth
is
40
000
km
1
Complete
the
following
table
:
Circonférence
Echelle
Actual
size
(m)
Reduced
size
(m)
2
Complete
the
dotted
lines
with
the
correct
value
:
ˇ
The
scale
of
this
thumbnail
is
1
:
:
:
:
:
:
ı
Definition:
scale
of
a
reduction
is
the
coefficient
of
pro-portionality
to
go
from
ˇactual
sizeı
to
ˇtaille
réduiteı.
E.893
The
car
below
is
a
reduction
of
the
Ferrari
F40.
In
reality,
its
length
is
4.44
meters.
1
a
Give
the
scale
of
this
representation
b
Knowing
that
the
car
(the
real
one)
is
1.98
meters
wide,
give
the
width
of
this
reduction
to
the
nearest
millime-ter.
2
Another
reduction
of
this
car
is
offered
to
scale
1
37
.
Give
the
length
of
this
new
reduction.
4.
Evolutions:
introduction
E.9228
In
one
year,
the
price
of
an
object
increased
from
130
e
to
149.5
e
.
We
wish
to
determine
the
percentage
increase
experienced
by
the
price
of
this
object
in
1
year.
1
By
what
amount
did
the
price
of
this
item
increase?
2
Complete
the
table
below
:
Référence
Augmentation
Prix
Pourcentage
100
%
3
Complete
the
operations
below
to
obtain
the
percentage
increase
experienced
by
the
price
of
this
object
:
From
the
cross
product
:
x
×
:
:
:
=
:
:
:
×
:
:
:
We
derive
:
x
=
:
:
:
×
:
:
:
:
:
:
=
:
:
:
%
https://chingmath.fr
chapExoCorrec/11524
sacados/11524
chapExoCorrec/11525
sacados/11525
chapExoCorrec/11526
sacados/11526
chapExoCorrec/11527
sacados/11527
chapExoCorrec/874
sacados/874
chapExoCorrec/9236
sacados/9236
chapExoCorrec/898
sacados/898
chapExoCorrec/887
sacados/887
chapExoCorrec/893
sacados/893
chapExoCorrec/9228
sacados/9228
Valeur initialeAugmentationValeur ∏nale30050251215020%%
Valeur initialeRéductionValeur ∏nale200501204405512%−12%
E.894
In
one
year,
the
number
of
students
at
a
school
has
decreased
from
1025
students
to
943
students.
We
wish
to
determine
the
percentage
reduction
in
enrollment
for
this
facility:
1
By
how
many
students
has
the
school’s
enrollment
de-creased?
2
Complete
the
table
below
:
Référence
Réduction
Effectif
Pourcentage
100
%
3
Complete
the
operations
below
to
obtain
the
percentage
reduction
experienced
by
the
facility’s
workforce:
From
the
cross
product
:
x
×
:
:
:
=
:
:
:
×
:
:
:
We
derive
:
x
=
:
:
:
×
:
:
:
:
:
:
=
:
:
:
%
E.7919
1
In
order
to
perform
an
augmentation
of
20
%
on
a
set
of
values,
we
use
the
table
below
to
complete
:
2
Justify
that
the
rows
ˇ
Initial
value
ı
and
ˇ
Final
Value
ı
represent
a
proportionality
situation
for
which
the
pro-portionality
coefficient
will
be
specified.
E.7918
1
In
order
to
perform
a
reduction
of
12
%
on
a
set
of
values,
we
use
the
table
below
to
complete
:
2
Justify
that
the
rows
ˇ
Initial
value
ı
and
ˇ
Final
Value
ı
represent
a
proportionality
situation
for
which
the
pro-portionality
coefficient
will
be
specified.
5.
Evolution
and
proportionality
coefficient
E.872
Proposal:
When
a
quantity
increases
by
a
%
,
the
multiplier
coef-ficient
that
reflects
this
change
has
a
value
of
1+
a
100
.
When
a
quantity
decreases
by
a
%
,
the
multiplier
coef-ficient
that
reflects
this
change
has
a
value
of
1
−
a
100
.
Match
each
of
the
following
changes
with
the
appropriate
mul-tiplier
coefficient
:
a
10
%
b
12
%
c
2
%
d
112
%
e
10
%
f
25
%
E.9232
Proposal:
Consider
a
change
with
a
multiplier
coefficient
of
k
:
If
k>
1
,
then
this
change
is
an
increase
with
a
percent-age
increase
of
a
,
which
has
a
value
of
:
a
=
k
−
1
×
100
If
k<
1
,
then
this
change
is
a
decrease,
the
percentage
a
of
which
is
:
a
=
1
−
k
×
100
Associate
each
of
the
following
multiplier
coefficients
with
the
nature
of
the
corresponding
change
and
its
associated
percent-age:
a
1
;
05
b
0
;
8
c
1
;
2
d
0
;
95
e
1
;
4
f
0
;
6
E.10918
1
Associate
the
appropriate
multiplying
factor
with
each
of
the
following
changes
:
a
20
%
b
3
%
c
7.5
%
2
Associate
with
each
of
the
following
multiplier
coeffi-cients,
the
nature
of
the
corresponding
evolution
and
its
associated
percentage:
a
1.3
b
0.9
c
1.88
https://chingmath.fr
chapExoCorrec/894
sacados/894
chapExoCorrec/7919
sacados/7919
Valeur initialeAugmentationValeur ∏nale30050251215020%%
chapExoCorrec/7918
sacados/7918
Valeur initialeRéductionValeur ∏nale200501204405512%−12%
chapExoCorrec/872
sacados/872
chapExoCorrec/9232
sacados/9232
chapExoCorrec/10918
sacados/10918
E.10946
1
Associate
the
appropriate
multiplying
factor
with
each
of
the
following
changes
:
a
13
%
b
18
%
c
1.2
%
2
Associate
with
each
of
the
following
multiplier
coeffi-cients,
the
nature
of
the
corresponding
evolution
and
its
associated
percentage:
a
1.1
b
0.73
c
1.31
E.1126
1
To
make
an
increase
of
12
%
,
multiply
by
.
.
.
.
.
.
.
.
.
the
old
price.
2
To
make
an
increase
of
.
.
.
.
.
.
.
.
.
%,
multiply
by
1.45
the
old
price.
3
To
make
a
decrease
of
12
%
,
multiply
by
.
.
.
.
.
.
.
.
.
the
old
price.
4
To
make
a
decrease
of
.
.
.
.
.
.
.
.
.
%,
multiply
by
0.23
the
old
price.
E.5573
1
What
is
the
multiplier
associated
with
an
increase
of
5
%
?
2
What
is
the
multiplier
associated
with
a
reduction
of
5
%
?
6.
Evolution:
search
for
future
value
E.9233
A
merchant
increases
in
January
2002
the
prices
of
all
its
items
from
12%
.
1
Give
the
multiplier
coefficient
associated
with
this
change.
2
A
DVD
player
costs,
before
increase,
372
euros.
How
much
will
it
cost
afterwards?
E.9234
A
merchant
increases
the
prices
of
all
his
items
by
8
%
.
1
Give
the
multiplier
coefficient
associated
with
this
evo-lutino.
2
A
DVD
player
costs,
before
increase,
329
euros.
How
much
will
it
coùt
after?
E.885
The
selling
price,
excluding
tax,
of
a
surfboard
is
23
000
F
.
One
must
pay
a
TV
A
(value
added
tax)
of
18
%
.
Calculate
the
selling
price,
to
the
public,
of
this
surfboard.
E.899
1
Give
the
multiplier
coefficient
associated
with
a
reduc-tion
of
7.5
%
.
2
An
object
costs
132
e
and
undergoes
a
reduction
of
7.5
%
.
What
is
its
new
price
after
the
discount
is
applied?
E.892
A
store
specializing
in
the
sale
of
automobile
accessories
sells
a
model
of
tire
at
120
e
unit.
During
a
promotion,
he
decides
to
offer
a
discount
of
25
%
on
the
purchase
of
each
tire.
Its
advertising
poster
states
:
ˇLe
4
e
tire
is
gratuitı.
Is
this
correct?
Justify.
7.
Evolution:
search
for
the
initial
value
E.884
In
January
2002
,
a
retailer
increases
the
prices
of
all
its
items
at
12%
.
1
Give
the
multiplier
coefficient
associated
with
this
evolu-tion.
2
A
television
set
costs,
after
increase,
476
euros.
How
much
did
it
cost
before?
E.891
A
retailer
increases
the
prices
of
all
its
products
at
8
%
.
1
Give
the
multiplier
coefficient
associated
with
this
evolu-tion.
2
A
television
set
costs,
after
increase,
540
euros.
How
much
did
it
cost
before?
E.9238
An
object,
after
undergoing
a
reduc-tion
of
12
%
,
costs
48.4
e
.
What
was
the
price
of
this
object
before
the
reduction?
E.900
A
shopkeeper
increases
the
prices
of
all
his
items
by
8%
.
1
A
DVD
player
costs,
before
increase,
329
euros.
How
much
will
it
cost
afterwards?
2
A
television
costs,
after
increase,
540
euros.
How
much
did
it
cost
before?
E.1424
An
appliance
store
is
offering
a
dis-count
of
12
%
on
all
its
items.
1
A
television
set
cost
245
e
.
What
will
its
new
price
be?
2
The
price
of
a
dryer
after
this
discount
is
435.6
e
.
Deter-mine
the
initial
price
of
this
dryer
E.1457
In
one
store,
the
owner
raises
all
his
prices
by
12
%
.
1
A
video
recorder
cost
215
e
before
increase.
Give
the
price
of
this
object
after
undergoing
the
increase.
2
And
a
DVD
player
has
undergone
an
increase
of
36
e
.
De-termine
the
price
of
this
DVD
player
before
the
increase
and
its
price
after
the
increase.
https://chingmath.fr
chapExoCorrec/10946
sacados/10946
chapExoCorrec/1126
sacados/1126
chapExoCorrec/5573
sacados/5573
chapExoCorrec/9233
sacados/9233
chapExoCorrec/9234
sacados/9234
Groupe Ouest - Juin 2003
chapExoCorrec/885
sacados/885
chapExoCorrec/899
sacados/899
chapExoCorrec/892
sacados/892
chapExoCorrec/884
sacados/884
chapExoCorrec/891
sacados/891
Groupe Ouest - Juin 2003
chapExoCorrec/9238
sacados/9238
chapExoCorrec/900
sacados/900
Groupe Ouest - Juin 2003 - 2 points
chapExoCorrec/1424
sacados/1424
chapExoCorrec/1457
sacados/1457
E.1421
1
a
Aline
goes
shopping
in
a
store
running
promotions.
She
buys
an
item
originally
worth
36
e
and
discounted
by
25
%
.
Calculate
its
new
price.
b
Another
item
cost
20.4
e
after
a
discount
of
15
%
.
De-
termine
the
initial
price
of
this
object.
2
Give
the
purchase
price
of
these
two
items
before
their
reduction,
then
after
their
reduction.
Deduct
the
total
percentage
discount
on
his
two
pur-chases.
8.
Developments:
rate
search
E.2116
Answer
the
following
questions.
No
justification
is
required
:
1
The
price
of
an
object
has
been
multiplied
by
1.56
.
What
is
the
associated
percentage
increase?
2
The
number
of
pupils
in
a
school
has
fallen.
This
num-ber
has
been
multiplied
by
0.86
.
What
is
the
associated
percentage
reduction?
E.886
In
a
store,
a
video
recorder
costs
34
000
F
and
is
sold
at
a
price
of
25
500
F
.
What
is
the
percentage
reduction
from
the
original
price?
E.9230
During
the
sale
period,
the
listed
price
of
a
dress
is
4
500
F
.
After
discount,
the
sale
price
of
this
dress
is
3
825
F
.
What
is
the
percentage
of
this
discount?
E.9235
Answer
the
following
questions.
No
justification
is
required
:
1
An
object
increased
from
112
e
à
156.8
e
.
What
was
the
percentage
increase?
2
A
sale
item
costing
4
000
FCFA
shows
a
discount
of
1
500
FCA
.
What
is
the
percentage
discount
given?
E.9237
Arrived
the
month
of
July,
the
sales
begin
in
France.
A
store
displays
−
15
%
on
all
items
in
its
store.
A
sweater
went
from
:
40
e
à
34.4
e
.
Explain
why
the
owner
has
been
falsely
advertising.
9.
Evolution:
initial
value,
future
value
and
evolution
rate
E.1127
In
its
1995
census,
Mexico
had
91.15
million
inhabitants.
Whereas
in
2000
,
there
were
97.48
mil-lion
inhabitants.
1
What
is
the
percentage
increase
in
population
between
these
two
dates?
Round
to
the
nearest
tenth.
2
Whereas
between
1980
and
2000
,
the
population
grew
by
43.1%
.
Give
the
population
of
Mexico
in
1980
?
Round
the
result
to
the
nearest
ten
thousand
inhabitants.
E.3377
Heimriri
and
her
brother
Tehui
want
to
spoil
their
mom
for
Mother’s
Day.
They
have
18
000
F
and
take
advantage
of
the
sales.
1
In
the
window
of
a
jewelry
store,
they
see
beautiful
12
000
F
earrings.
Calculate
the
price
of
the
earrings
after
a
discount
of
25
%
?
2
In
the
same
jewelry
store,
they
see
a
beautiful
ring.
After
a
discount
of
20
%
,
the
price
of
the
ring
is
7
840
F
.
What
was
its
original
price?
3
As
Heimriri
prepares
to
leave
the
jewelry
store,
she
is
charmed
by
a
mother-of-pearl
pendant.
Here’s
what
the
tag
says
:
Pendant
2
800
F
2
100
F
Determine
the
percentage
discount
taken
on
the
price
of
this
pendant.
10.
Successive
evolutions
E.9229
A
toy
costs
100
e
.
It
is
first
reduced
by
10
%
,
then
by
a
second
reduction
of
10
%
:
1
What
is
the
selling
price
of
this
toy
after
these
two
dis-counts?
2
What
is
the
total
ˇ
percentage
ı
of
the
discount
allocated
to
this
toy?
https://chingmath.fr
chapExoCorrec/1421
sacados/1421
chapExoCorrec/2116
sacados/2116
chapExoCorrec/886
sacados/886
chapExoCorrec/9230
sacados/9230
chapExoCorrec/9235
sacados/9235
chapExoCorrec/9237
sacados/9237
chapExoCorrec/1127
sacados/1127
chapExoCorrec/3377
sacados/3377
chapExoCorrec/9229
sacados/9229
Réduction de10%Réduction de32%Augmentation de5%Augmentation de1%px↦−1;05×xpx↦−0;68×xpx↦−0;9×xpx↦−1;01×x
E.7971
The
manager
of
the
largest
multi-sport
club
in
the
region
noted
that
between
2010
Jan-uary
1
er
and
2012
December
31
,
the
total
number
of
members
increased
by
10
%
,
and
then
increased
again
by
5
%
between
2013
January
1
er
and
2015
December
31
.
The
total
number
of
members
in
2010
was
1
000
.
1
Calculate
and
justify
the
total
number
of
members
on
31
December
2012
.
2
Calculate
and
justify
the
total
number
of
members
on
December
31
2015
.
3
Martine
thinks
that
on
December
31
2015
,
there
should
be
1
150
members,
because
she
says
:
ˇ
an
increase
of
10
%
followed
by
another
increase
of
5
%
,
which
makes
a
total
increase
of
15
%
ı.
What
do
you
think?
Explain
your
answer.
E.9231
Note:
All
attempts,
ideas,
and
approaches,
even
if
unsuc-cessful
or
poorly
formulated,
will
be
taken
into
account
for
evaluation
purposes.
An
item
undergoes
a
successive
increase
of
5
%
followed
by
a
reduction
of
5
%
.
Will
the
price
of
the
item
change?
Please
specify
your
answer.
11.
Evolution
and
affine
functions
E.7924
Each
evolution
is
associated
with
a
linear
function.
For
each
of
the
proposed
evolutions,
associate
the
corresponding
linear
function
:
12.
Share
E.4921
1
A
dictionary
costs
25
e
.
An
increase
of
16
%
is
applied
to
the
price
of
this
item.
Give
the
new
price
of
the
dictionary.
2
A
television
has
its
price
increased
from
375
e
à
270
e
during
a
sale.
Give
the
percentage
discount
applied
to
the
price
of
this
item.
Justify
your
answer.
E.10947
1
A
television
costs
191
e
.
A
reduction
of
11
%
is
applied
to
the
price
of
this
item.
Give
the
new
price
of
the
television.
2
A
cell
phone
has
its
price
increased
from
424
e
à
477
e
.
Give
the
percentage
increase
applied
to
the
price
of
this
item.
Justify
your
answer.
13.
Unclassified
exercises
E.1131
A
store
makes
a
discount
of
15
%
on
its
entire
store
during
the
sale
period.
1
Help
him
by
telling
him
how
much
to
multiply
the
old
prices
by
to
make
the
label
change.
2
A
television
set
costs,
before
discounting,
599
e
.
What
is
its
price
after
discounting?
3
After
reduction,
a
DVD
player/writer
costs
248.2
e
.
What
was
its
price
before
discount?
https://chingmath.fr
chapExoCorrec/7971
sacados/7971
chapExoCorrec/9231
sacados/9231
chapExoCorrec/7924
sacados/7924
Réduction de10%Réduction de32%Augmentation de5%Augmentation de1%px↦−1;05×xpx↦−0;68×xpx↦−0;9×xpx↦−1;01×x
chapExoCorrec/4921
sacados/4921
chapExoCorrec/10947
sacados/10947
chapExoCorrec/1131
sacados/1131
12345ABCDEFGx7580859095100
12345ABCDEFGx75808590951009095100105110115420445470495520545405430455480505530
120m60m30m90mABCD(départ)EFGHIJKL
E.6281
Pauline’s
uncle
regularly
partic-ipates
in
a
(sailboat
race)
organized
every
year
on
the
same
stretch
of
water.
In
2012
,
he
completed
the
course
consisting
of
two
short
and
three
long
loops
in
8
hours
and
40
minutes.
When
she
participated
in
2013
,
it
took
her
8
hours
and
25
minutes
to
complete
the
course
consisting
of
three
short
and
two
long
loops
that
year.
He
remembers
that
he
did
not
complete
any
loop
in
less
than
75
minutes.
He
also
knows
that
it
took
him
15
minutes
longer
to
run
the
long
loop
than
it
did
to
run
the
short
loop.
However,
he
wants
to
know
how
long
it
took
him
to
sail
the
short
loop
and
the
long
loop
on
his
sailboat.
1
Convert
the
times
achieved
for
these
2012
and
2013
runs
to
minutes.
2
Pauline
decided,
using
a
spreadsheet,
to
help
her
uncle
determine
the
times
for
the
short
loop
as
well
as
for
the
long
loop.
A
copy
of
the
resulting
screen
is
given
below
:
She
noted
x
the
duration
in
minutes
for
the
short
loop.
a
What
formula
for
obtaining
the
time
in
minutes
needed
to
run
the
long
loop
will
she
enter
in
cell
B2
?
b
She
will
enter
in
cell
B3
the
formula
ˇ
=2*B1+3*B2
ı.
What
does
this
formula
calculate?
c
What
formula
will
she
enter
in
cell
B4
to
calculate
the
travel
time
when
she
attends
2013
?
She
then
copied
the
formulas
entered
in
B2
,
B3
,
and
B4
to
the
right
and
got
the
following
screen
:
3
If
she
enters
the
number
105
in
cell
H1
,
what
values
will
she
get
in
cells
H2
,
H3
,
and
H4
?
4
Using
the
copy
of
the
screen
obtained
with
the
spread-sheet,
specify
the
times
needed
for
his
uncle
to
walk
the
short
loop
as
well
as
to
walk
the
long
loop.
E.10836
A
professional
and
an
amateur
are
going
to
do
a
karting
session
on
the
track
below
(shown
in
solid
lines)
.
This
track
is
made
up
of
segments,
half
circles
and
quarter
circles.
The
professional
makes
a
lap
in
60
seconds.
The
amateur
makes
a
lap
in
72
seconds.
1
Show
that
the
length
of
the
runway
is
1
045
m
,
rounded
to
the
nearest
unit.
Any
trace
of
research
will
be
valued.
2
Calculate
the
average
speed
of
the
professional
in
m
=
s
.
We’ll
round
to
the
nearest
hundredth.
3
For
safety
reasons
on
this
circuit,
amateurs
must
not
ex-ceed
60
km
=
h
average
speed.
Does
this
amateur
respect
the
safety
rules?
4
The
professional
and
the
amateur
start
at
the
same
time
from
the
starting
line
and
complete
several
laps
of
the
circuit.
Recall
that
the
professional
completes
one
lap
in
60
s
and
the
amateur
in
72
s
.
a
Decompose
60
and
72
into
a
product
of
prime
factors.
b
After
how
long
do
they
find
themselves
on
the
starting
line
together
for
the
first
time?
c
How
many
laps
will
they
each
have
completed
by
then?
E.1130
In
metropolitan
France,
in
2001
the
pop-ulation
was
60.9
million
while
in
1950
there
were
42
million
inhabitants
.
What
was
the
percentage
increase
in
population
between
these
two
dates?
(round
to
the
nearest
tenth)
https://chingmath.fr
chapExoCorrec/6281
sacados/6281
12345ABCDEFGx7580859095100
12345ABCDEFGx75808590951009095100105110115420445470495520545405430455480505530
chapExoCorrec/10836
sacados/10836
ex 5 polynesie juin 2023
120m60m30m90mABCD(départ)EFGHIJKL
chapExoCorrec/1130
sacados/1130