Question

According to the Guinness Book of World Records, a woman from Russia, Mrs. Vassilyeva, had 69 children between the years 1725 to 1765. She had 16 pairs of twins, 7 sets of triplets, and 4 sets of quadruplets. Suppose one of the births is randomly selected. Given that Mrs. Vassilyeva gave birth to at least 3 children (triplets), what is the probability that she gave birth to quadruplets

Answer 1

(E) 4/11

Explanation:

P(Mrs. Vassilyeva gave birth to quadruplets | she gave birth to at least triplets) = 4/11.

Of the 11 times she gave birth to at least triplets, 4 of those births were quadruplets.

Answer 2

36.36% probability that she gave birth to quadruplets

Explanation:

A probability is the number of desired outcomes divided by the number of total outcoes.

Desired outcomes:

Giving births to quadruplets.

She has 4 sets of quadruplets.

So
`D = 4`

Total outcomes:

At least 3 children(triplets).

7 sets of triplets and 4 sets of quadruplets.

So
`T = 7 + 4 = 11`

Probability:

`p = (D)/(T) = (4)/(11) = 0.3636`

36.36% probability that she gave birth to quadruplets