Question

Elizabeth brought a box of donuts to share. There are​ two-dozen (24) donuts in the​ box, all identical in​ size, shape, and color. Three are​ jelly-filled, 8 are​ lemon-filled, and 13 are​ custard-filled. You randomly select one​ donut, eat​ it, and select another donut. Find the probability of selecting two jelly​-filled donuts in a row.

Answer 1

1/92

Explanation:

There are C(3, 2) = 3 ways to select 2 jelly-filled donuts from the 3 in the box. There are C(24, 2) = 276 ways to select 2 donuts from the box.

The probability that you will select 2 jelly-filled donuts is ...

... 3/276 = 1/92

_____

C(n, k) = n!/(k!(n-k)!)

C(3, 2) = (3·2)/2 = 3

C(24, 2) = (24·23)/2 = 276