Question

A box contains 720 marbles. The result of 20 marbles pulled at random from the box is given below. • 5 red marbles • 6 blue marbles • 3 green marbles • 4 black marbles • 2 yellow marbles Based on this information, how many yellow marbles could be expected in the box? A) 64 B) 72 C) 88 D) 100

Answer 1

20 is the size of a random sample of 720 marbles.

Notice that 720=20*36

If there are 2 yellow marbles in the sample of 20 marbles, then we can expect:

2*36=72 yellow marbles in the box of 720 marbles

So, B) 72 is the correct answer