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112233445566BleuRouge
E.11392
The
school
administration
takes
stock
of
the
students
enrolled
in
the
half-board
program
:
The
school
has
852
students
;
In
total,
there
are
213
students
enrolled
in
the
ˇ
day
stu-dent
ı
;
program
For
girls,
123
girls
are
enrolled
in
the
ˇ
day
stu-dent
ı
program
and
312
are
enrolled
in
the
half-board
program
1
Complete
the
table
below
:
Boys
Filles
Total
Day
student
Half-board
Total
2
A
student
is
chosen
at
random
from
the
list
of
students
:
a
What
is
the
probability
that
the
student
is
a
girl?
b
What
is
the
probability
that
the
student
is
a
half-boarder?
c
Knowing
that
the
student
is
a
boy,
what
is
the
proba-bility
that
he
is
a
day
student?
E.11427
We
are
interested
in
three
sixth-grade
classes
at
a
school.
Volleyball
and
soccer
are
offered
as
ex-tracurricular
activities
and
together
have
354
members.
Here
is
some
additional
information
that
has
been
gathered
:
76
girls
have
signed
up
for
volleyball
There
are
132
members
in
the
volleyball
club.
There
are
238
boys.
1
Complete
the
table
:
Volleyball
Soccer
Total
Boys
Girls
Total
2
We
randomly
select
a
sixth
grader
:
a
What
is
the
probability
that
this
student
plays
volley-ball?
b
What
is
the
probability
that
this
student
is
a
girl?
c
Knowing
that
the
student
chosen
is
a
boy,
what
is
the
probability
that
he
plays
soccer?
E.11618
On
s’intéresse
à
trois
classes
de
sixièmes
d’un
établissement
scolaire.
Le
Volley-ball
et
le
Football
sont
proposés
en
activité
extra-scolaire
et
regroupent
à
eux
deux
354
adhérents.
Voici
quelques
informations
complémentaires
recueillies:
76
filles
se
sont
inscrites
au
Volley-Ball.
Le
Volley-Ball
compte
132
adhérents.
Les
garçons
sont
au
nombre
de
238.
1
Compléter
le
tableau
:
Volley-ball
Football
Total
Garçons
Filles
Total
2
On
choisit
au
hasard
un
élève
de
sixième:
a
Quelle
est
la
probabilité
que
cet
élève
pratique
le
Volley-ball
?
b
Quelle
est
la
probabilité
que
cet
élève
soit
une
fille
?
c
Sachant
que
l’élève
choisi
est
un
garçon,
quelle
est
la
probabilité
qu’il
pratique
le
Football
?
4.
Non-equiprobable
situation
E.11509
A
random
experiment
con-sists
in
rolling
two
dice,
red
and
blue,
with
six
faces
simultaneously
and
considering
the
sum
ob-tained
by
these
two
dice.
The
dice
are
assumed
to
be
perfectly
balanced.
1
Describe
the
universe
of
possible
outcomes.
2
a
Complete
the
ta-ble
below
:
https://chingmath.fr
chapExoCorrec/11392
sacados/11392
chapExoCorrec/11427
sacados/11427
chapExoCorrec/11618
sacados/11618
chapExoCorrec/11509
sacados/11509
112233445566BleuRouge
EvènementsélémentairesNNNNNNNBBNNNNNNNNBBNBNNBNNBBBB1ertirage2etirage
RRBRRRBRRRBBReprésentation 1
RBRRBRRRBReprésentation 2
V2F2F2F2V1V2F2F2F2F1V2F2F2F2F1V2F2F2F2F1
a
Determine
the
probability
law
associated
with
this
random
experiment.
5.
Choice
trees
E.7655
An
urn
contains
two
black
balls
and
one
white
ball;
the
game
is
played
with
the
ball
being
returned
:
i.e.,
once
the
ball
has
been
drawn,
it
is
returned
to
the
urn
before
the
next
draw.
Here’s
a
decision
tree
based
on
the
drawing
of
two
balls
:
1
Taking
into
account
the
order
in
which
the
balls
are
drawn,
what
is
the
possible
number
of
different
draws?
2
Determine
the
probability
of
the
following
events
:
a
A
:
ˇ
The
first
ball
drawn
is
blanche
ı.
b
B
:
ˇ
The
two
balls
drawn
are
différentes
ı
colors.
c
C
:
ˇ
The
second
ball
is
a
noire
ı
ball.
3
Give
the
probabilities
of
the
following
events
:
a
A
∩
B
b
A
∩
C
c
A
∪
C
E.7662
An
urn
contains
two
red
balls
and
one
blue
ball
indistinguishable
by
touch.
Using
this
urn,
we
construct
two
sets
:
We
draw
a
first
ball
from
the
urn,
then
without
putting
it
back,
we
draw
a
second
ball.
A
first
ball
is
drawn
from
the
urn,
its
color
observed
and
then
returned
to
the
urn.
A
second
ball
is
then
drawn.
In
both
games,
the
game
is
considered
won
if
the
two
balls
drawn
are
of
the
same
color.
The
two
choice
trees
below
are
proposed
:
1
Associate
with
each
of
the
games
its
representation
in
the
form
of
a
choice
tree.
2
Determine
the
probability
of
winning
for
each
of
its
games.
E.7658
A
QCM
(multiple-choice
questionnaire)
is
proposed
to
students
:
it
comprises
two
questions
and
four
answers
are
proposed,
only
one
of
which
is
correct.
We
wish
to
study
the
percentage
of
success
in
this
MCQ
if
the
students
answer
it
completely
at
random
;
we
then
assume
that
the
answers
given
to
each
of
the
questions
are
indepen-dent
of
each
other.
We
note
:
F
i
:
ˇ
The
answer
provided
to
question
i
is
fausse
ı
;
V
i
:
ˇ
The
answer
provided
to
the
question
i
is
vraie
ı
;
Here
is
the
choice
tree
associated
with
this
situation
:
Consider
the
random
experiment
of
randomly
selecting
the
answers
to
these
two
questions
1
Give
the
probability
of
obtaining
the
two
correct
answers.
2
Give
the
probability
of
obtaining
only
one
correct
answer.
https://chingmath.fr
chapExoCorrec/7655
sacados/7655
EvènementsélémentairesNNNNNNNBBNNNNNNNNBBNBNNBNNBBBB1ertirage2etirage
chapExoCorrec/7662
sacados/7662
RRBRRRBRRRBBReprésentation 1
RBRRBRRRBReprésentation 2
chapExoCorrec/7658
sacados/7658
V2F2F2F2V1V2F2F2F2F1V2F2F2F2F1V2F2F2F2F1
NNNBNBNNNNBNBNNBNNBNB
123546UrneBUrneA
213214215216
122564UrneBUrneA
VFFFVVFFFFVFFFFVFFFFVVFFFVVFFFFVFFFFVFFFFFVFFFVVFFFFVFFFFVFFFFFVFFFVVFFFFVFFFFVFFFFF
141414V34FV3414V34FFV341414V34FV3414V34FFF
E.11510
An
urn
contains
two
black
balls
and
one
white
ball;
the
game
consists
of
extracting
two
balls
from
the
urn
without
delivery:
the
first
ball
drawn
will
not
be
returned
to
the
urn.
Opposite
is
a
choice
tree
repre-senting
the
draws
in
this
game.
1
Taking
into
account
the
order
in
which
the
balls
are
drawn,
what
is
the
possible
number
of
different
draws?
2
Determine
the
probability
of
the
following
events
:
a
A
:
ˇ
The
first
ball
drawn
is
blanche
ı.
b
B
:
ˇ
The
second
ball
drawn
is
blanche
ı.
c
C
:
ˇ
The
two
balls
drawn
are
distinctes
ı
colors.
3
Give
the
probabilities
of
the
following
events
:
a
A
∩
B
b
A
∩
C
c
C
E.11619
On
considère
deux
urnes
contenant
des
boules
sur
lesquelles
est
inscrit
un
chiffre.
L’expérience
aléa-toire
consiste
à
tirer
une
boule
au
hasard
dans
l’urne
A,
puis
une
boule
au
hasard
dans
l’urne
B
et
à
faire
la
somme.
1
Voici
le
contenu
de
l’urne
:
On
associe
à
cette
expérience
l’arbre
de
choix:
Quelle
est
la
probabilité
d’obtenir
la
somme
6
?
2
On
modifie
les
urnes
:
a
Construire
l’arbre
de
choix
correspondant
à
cette
ex-périence.
b
Quelle
est
la
probabilité
d’obtenir
la
somme
7
?
6.
Probability
tree
E.7656
Consider
a
multiple-choice
questionnaire
consisting
of
3
questions,
each
offering
4
answers,
only
one
of
which
is
correct.
A
random
experiment
is
created
by
asking
participants
to
answer
the
questions
in
the
form
at
random.
This
situation
is
represented
by
the
decision
tree
below
:
1
Complete
the
probability
table
below
:
k
0
1
2
3
Probability
of
obtaining
k
correct
answers
Note
that
for
each
multiple-choice
question,
the
probability
of
getting
a
correct
answer
is
1
4
and
a
wrong
answer
is
3
4
.
We
simplify
the
decision
tree
with
the
probability
tree
below
:
We
want
to
find
the
results
of
question
1
using
this
proba-
https://chingmath.fr
chapExoCorrec/11510
sacados/11510
NNNBNBNNNNBNBNNBNNBNB
chapExoCorrec/11619
sacados/11619
123546UrneBUrneA
213214215216
122564UrneBUrneA
chapExoCorrec/7656
sacados/7656
VFFFVVFFFFVFFFFVFFFFVVFFFVVFFFFVFFFFVFFFFFVFFFVVFFFFVFFFFVFFFFFVFFFVVFFFFVFFFFVFFFFF
141414V34FV3414V34FFV341414V34FV3414V34FFF
ESESESESESESES
ESESESESESESES
NNNBNNNNBNNNNBNNNNBB
NNNBBNNNNBBNNNNBBNNNNBBBNNNBBB
bility
tree
:
2
a
Which
calculation,
using
the
data
from
the
tree
be-low,
allows
us
to
find
the
probability
of
getting
3
cor-rect
answers
to
Q
.
C
.
M
.
?
b
Which
calculation,
using
the
data
from
the
tree
below,
allows
us
to
find
the
probability
of
obtaining
0
correct
answers
to
Q
.
C
.
M
.
?
c
Which
calculation,
using
the
data
from
the
tree
below,
allows
us
to
find
the
probability
of
obtaining
1
correct
answers
to
Q
.
C
.
M
.
?
E.7670
Consider
a
Bernoulli
scheme
with
pa-rameters
3
and
0.4
.
1
Complete
the
probability
tree
below
:
2
How
many
outcomes
does
this
random
experiment
have?
3
Determine
the
probability
of
obtaining
3
success.
4
a
How
many
outcomes
represent
2
success?
b
Determine
the
probability
of
obtaining
2
success
in
this
random
experiment.
E.7671
Consider
a
Bernoulli
scheme
with
pa-rameters
4
and
0.4
.
1
Complete
the
probability
tree
below
:
2
How
many
outcomes
does
this
random
experiment
have?
3
Determine
the
probability
of
obtaining
4
success.
4
a
How
many
outcomes
represent
3
success?
b
Determine
the
probability
of
obtaining
3
success
in
this
random
experiment.
7.
Binomial
law
E.7681
1
There
are
four
balls
in
an
urn
:
three
black
balls
and
one
white
ball.
Two
balls
are
drawn
successively
from
this
urn,
with
delivery.
The
choice
tree
below
illustrates
all
the
elementary
events
in
this
random
experiment
:
a
Construct
the
associated
probability
tree
b
Note
X
the
random
variable
associating
the
number
of
white
balls
drawn.
Determine
the
following
probabili-ties
:
P
X
=0
;
P
X
=2
2
In
an
urn
are
five
balls
:
three
black
balls
and
two
white
balls.
Two
balls
are
drawn
successively
from
this
urn,
with
delivery.
The
choice
tree
below
illustrates
all
the
elementary
events
in
this
random
experiment
:
a
Construct
the
associated
probability
tree
b
Note
X
the
random
variable
associating
the
number
of
white
balls
drawn.
Determine
the
following
probabili-ties
:
P
X
=1
;
P
X
=2
E.7682
1
a
Construct
a
probability
tree
associated
with
a
Bernoulli
scheme
of
parameter
2
and
0.4
.
b
Note
X
a
random
variable
following
a
binomial
distri-bution
of
parameter
2
and
0.4
.
Determine
the
follow-ing
probabilities
:
P
X
=0
;
P
X
=1
2
a
Construct
a
probability
tree
associated
with
a
Bernoulli
scheme
with
parameters
3
and
0.4
.
b
Note
X
a
random
variable
following
a
binomial
distri-bution
of
parameter
3
and
0.4
.
Determine
the
follow-ing
probabilities
:
P
X
=0
;
P
X
=1
https://chingmath.fr
chapExoCorrec/7670
sacados/7670
ESESESESESESES
chapExoCorrec/7671
sacados/7671
ESESESESESESES
chapExoCorrec/7681
sacados/7681
NNNBNNNNBNNNNBNNNNBB
NNNBBNNNNBBNNNNBBNNNNBBBNNNBBB
chapExoCorrec/7682
sacados/7682
12345678910
8.
Binomial
law
and
expectation
E.7720
Proposition:
The
expectation
of
a
random
variable
X
fol-lowing
a
binomial
distribution
with
parameters
n
and
p
is
the
number
n
×
p
and
is
denoted
by
E
(
X
)
.
Interpretation
:
The
expectation
is
the
observed
mean
value
of
the
number
of
successes
achieved
in
the
Bernoulli
scheme
when
this
random
experiment
is
performed
a
large
number
of
times.
1
Consider
a
random
variable
X
following
the
binomial
dis-tribution
with
parameters
10
and
0
;
3
.
Determine
the
expectation
of
the
random
variable
X
.
2
Consider
a
random
variable
X
following
the
binomial
dis-tribution
with
parameters
24
and
0
;
45
.
Determine
the
expectation
of
the
random
variable
X
.
E.7680
Five
boys
and
three
girls
write
their
names
on
a
piece
of
paper
and
insert
it
into
an
urn.
Two
pieces
of
paper
are
drawn
successively
from
the
urn,
with
a
discount.
The
two
draws
are
considered
to
be
independent.
1
At
each
draw,
we
look
to
see
whether
the
paper
drawn
designates
a
boy
or
a
girl.
Construct
the
probability
tree
related
to
this
experiment.
2
Let
X
be
the
random
variable
associating
with
an
out-come
of
this
draw
the
number
of
girls
selected.
a
Determine
the
probability
distribution
of
X
.
b
Calculate
its
mathematical
expectation
of
E
(
X
)
.
The
result
will
be
rounded
to
the
nearest
thousandth.
E.7685
We
have
a
well-balanced
cubic
die
whose
faces
are
numbered
from
1
to
6
.
When
rolling
the
dice,
the
game
is
considered
won
if
an
even
value
is
obtained.
We
roll
the
well-balanced
die
three
times
in
succession
and
denote
by
X
the
number
of
times
an
even
number
was
ob-tained.
1
Draw
up
the
probability
tree
associated
with
this
random
experiment.
2
Give
the
exact
value,
then
the
value
rounded
to
the
thou-sandth
of
the
probability
P
(
X
=2)
.
3
Give
the
expectation
of
the
random
variable
X
.
9.
Binomial
law
and
representation
E.7686
Below
is
represented
the
law
of
the
random
variable
X
following
the
binomial
law
of
parameters
n
=10
and
p
=0.3
:
Give
an
approximate
value
for
the
following
probabilities
:
a
P
X
=1
b
P
X
=3
E.7689
Below
is
given
the
representation
of
the
law
of
a
random
variable
X
following
a
binomial
distribution
with
parameter
n
=10
and
p
=0.7
.:
Give
the
inequality
that
is
verified
:
a
P
X
<
5
0.5
b
P
X
<
5
0.5
10.
Binomial
law
and
calculator
E.7684
Consider
a
random
variable
X
following
a
binomial
distribution
with
parameters
0.2
and
20
.
Questions
will
be
answered
using
the
calculator.
Results
will
be
rounded
to
the
nearest
10
−
3
:
1
Determine
the
value
of
the
following
probabilities
:
a
P
X
=5
b
P
X
=9
2
Determine
the
value
of
the
following
probabilities
:
a
P
X
5
b
P
X
9
E.7807
Consider
a
random
variable
X
following
a
binomial
distribution
with
parameters
30
and
0.24
.
Questions
will
be
answered
using
the
calculator.
Results
will
be
rounded
to
the
nearest
10
−
3
:
1
Determine
the
value
of
the
following
probabilities
:
a
P
X
=10
b
P
X
=12
2
Determine
the
value
of
the
following
probabilities
:
a
P
X
10
b
P
X
18
https://chingmath.fr
chapExoCorrec/7720
sacados/7720
chapExoCorrec/7680
sacados/7680
chapExoCorrec/7685
sacados/7685
chapExoCorrec/7686
sacados/7686
12345678910
chapExoCorrec/7689
sacados/7689
chapExoCorrec/7684
sacados/7684
chapExoCorrec/7807
sacados/7807
E.7687
Consider
a
random
variable
X
following
the
binomial
distribution
with
parameters
n
=5
and
p
=0.63
.
The
probability
values
will
be
rounded
to
three
decimal
places.
1
Determine
the
following
probabilities
:
a
P
X
=0
b
P
X
=1
c
P
X
=5
2
Give
the
probability
of
event
X
4
.
E.7721
For
the
end-of-year
concert,
the
conservatory
auditorium
has
400
places
reserved
for
parents.
We’re
interested
in
the
number
X
of
parents
attending
the
end-of-year
concert
in
the
auditorium.
The
probability
of
each
500
parent
attending
the
concert
is
estimated
at
0.75
.
It
is
assumed
that
X
follows
the
binomial
distribution
with
parameters
500
and
0.75
.
1
Calculate
the
expectation
of
X
.
2
Determine
the
probability
that
the
number
of
seats
re-served
for
parents
is
sufficient.
Round
the
result
to
the
thousandth.
E.7688
A
vaccine
is
being
tested
on
a
popula-tion
of
100
individuals.
30
of
them
react
to
this
vaccine
with
high
fevers.
Each
test
phase
is
carried
out
on
a
group
of
5
in-dividuals
chosen
at
random
and
independently
between
each
test.
Let
us
note
X
the
random
variable
that
associates
with
each
test
phase
the
number
of
individuals
who
had
a
reaction
with
high
fevers.
1
Justify
that
the
random
variable
X
follows
a
binomial
distribution
with
parameters
5
and
0.3
.
2
Determine
the
probability
that
2
individuals
reacted
to
the
vaccine
with
fever
over
a
test
phase.
3
Over
a
test
phase,
what
is
the
probability
that
at
most
4
individuals
have
reacted
with
fever.
E.7690
By
choosing
a
pupil
at
random
from
among
those
registered
for
half-board,
we
know
that
the
prob-ability
of
the
chosen
pupil
being
satisfied
with
the
half-board
is
0.675
.
We
denote
X
the
random
variable
equal
to
the
number
of
stu-dents
declaring
to
be
satisfied
with
the
quality
of
the
meals.
As
the
number
of
students
is
sufficiently
large,
we
accept
that
X
follows
a
binomial
distribution
with
parameters
4
and
0.675
.
Results
will
be
rounded
to
the
thousandth.
1
Calculate
the
probability
of
the
event
A
:
ˇ
no
student
is
satisfait
ı.
2
Calculate
the
probability
of
the
event
B
:
ˇ
all
four
stu-dents
are
satisfied
with
the
quality
of
repas
ı.
11.
Fluctuation
interval
E.7852
A
farmer
sorts
his
tomatoes
according
to
their
size
(calibre)
.
He
tells
his
suppliers
that
40
%
of
his
tomatoes
are
of
a
calibre
greater
than
or
equal
to
6
(a
diameter
greater
than
47
mm
)
.
Visiting
the
farm,
a
supplier
takes
30
tomatoes
and
observes
that,
among
them,
10
tomatoes
are
of
a
size
greater
than
or
equal
to
6
.
Opposite
is
the
cumulative
distribution
function
of
a
binomial
random
variable
with
parameters
30
and
0.4
.
The
following
results
can
be
ex-tracted
from
it:
P
X
10
≈
0.2915
;
P
X
20
≈
0.9991
1
a
Determine
the
value
of
the
smallest
integer
a
that
satisfies
the
condition
:
P
X
a
>
0.025
b
Determine
the
value
of
the
smallest
integer
b
that
sat-isfies
the
condition
:
P
X
b
0.975
c
Deduce
the
fluctuation
interval
at
the
threshold
of
95
%
of
the
observed
frequency
for
the
random
variable
X
.
(The
limits
will
be
rounded
to
10
−
3
)
2
What
can
be
said
about
the
supplier’s
observation?
E.7853
Consider
a
random
variable
X
follow-ing
a
binomial
distribution
with
parameters
30
and
0.32
:
X∼B
30
;
0.32
k
0
1
2
3
4
5
6
7
8
P
(
X
k
)
0
0
0.001
0.005
0.018
0.049
0.11
0.208
0.341
k
9
10
11
12
13
14
15
16
17
P
(
X
k
)
0.494
0.645
0.774
0.871
0.934
0.97
0.988
0.995
0.999
k
18
19
20
21
22
23
24
25
26
27
28
29
30
P
(
X
k
)
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Determine
the
smallest
integers
a
and
b
such
that
:
P
X
a
)
>
0.025
;
P
X
b
0.975
2
Justify
that
:
P
a
X
b
0.95
3
Let
F
=
X
30
be
the
random
variable
representing
the
ran-dom
frequency
of
success.
Justify
that
:
P
a
30
F
b
30
0.95
12.
Unclassified
financial
years
https://chingmath.fr
chapExoCorrec/7687
sacados/7687
chapExoCorrec/7721
sacados/7721
chapExoCorrec/7688
sacados/7688
chapExoCorrec/7690
sacados/7690
chapExoCorrec/7852
sacados/7852
chapExoCorrec/7853
sacados/7853
E.11859
L’exercice
n’existe
pas.
https://chingmath.fr
sacados/11859