Find the missing probability. P(A)=720,P(A∩B)=49400,P(B)=?
P
(
A
)
=
7
20
,
P
(
A
∩
B
)
=
49
400
,
P
(
B
)
=
?

Work Shown:

Given info

P(A) = 7/20

P(A∩B)=49/400

P(B) = unknown

P(A∩B) = P(A)*P(B), assuming A and B are independent events

49/400 = (7/20)*P(B)

(7/20)*P(B) = 49/400

P(B) = (20/7)(49/400)

P(B) = (20*49)/(7*400)

P(B) = (20*7*7)/(7*20*20)

P(B) = 7/20

Note how

P(A∩B) = P(A)*P(B)

P(A∩B) = (7/20)*(7/20)

P(A∩B) = (7*7)/(20*20)

P(A∩B) = 49/400

which helps to confirm the answer.

no not all of them.

step-by-step explanation:

some of them have a square base.

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4