11.
From
a
lot
of
10
missiles,
4
are
selected
at
random
and
fired.
If
the
lot
contains
3
defective
missiles
that
will
not
fire,
what
is
the
probability
that
a)
All
4
will
fire?
f
),
inﬂ/
m
=t
Q@nﬂ
N
(5><
L{'B
b)
Atmc£
2w1lnot
re?
%ﬂ/»\%
_D}
@(DD)TQ(\
D\'b@@@
(z)
L
=
=
(f@
c)
None
wmflre
oY=
P
(4D
)
2O
fé'j
e
12.
On
the
average
a
certain
intersection
results
in
seven
traffic
accndents
per
week.
a)
What
is
the
probability
that
exactly
five
accidents
will
occur
at
this
intersection
in
any
given
week?
M=
al
A
,4
vaza
i
?
(D
A'A»—
ouweade,
\«
=1297
Two
accudents
in
a
given
day.
7,\/%
(oA
=
M%\
_
&

=1%3%
/___________,
c)
Atleast two
accidents
in
a
given
week.
o\
{9
'?;c_(,
_
'__7
fij»
=T
g\
=
\"Q(.OA,W&M\
@(glAch
CL\MQ@,"L\
=
~
=
\/T
_
/\,—
00q
_
L0064
=

QBt
&
Ul
2\
Two
accidents
given
we
will
have
at
leasiéio
accidents.c—
qu.a.o_J\
C\DCQAL
o"jr
9\\_
@CJACC/\

Q(Ql):z
aag\g&?@DQQé
A
e
Jfi'{
T
e
Qb
13.
On
the
average
a
secretary
makes
two
typing
errors
per
page.
What
is
the
probability
that
she
makes?
.
M=
Q\A?l}/)&,
/
a)
Four
or
more
errors
on
the:%tt;gge
she
types.
—ég\gg
&
L2
5
£
<
L~
.
\—(0
)R

P
3
=\
—
E5=
~
—
ST
=

1353~
3/707—«9707—
b)
No
errors?
¥
.
804
—~
O
Qloe).
%2_\—:
1353
@