Question

In a bin containing 500 marbles, 180 are red, 240 are blue, and 80 are green.

In a bowl of 25 marbles scooped from this bin, how many would be expected to be green?

Answer 1

80/500=0.16

0.16*25=4

Four marbles are expected to be green.

Answer 2

The bin has 500 marbles, out of which 180 are red, 240 are blue, and 80 are green. If a bowl of 25 marbles is scooped from this bin, then the number of green marbles will be in proportion to the original proportion of green marbles in the bin.

Thus, in the bin, the proportion of green marbles is
`(80)/(500)`. This same proportion will be maintained in the bowl of 25 marbles.

Let the expected number of green marbles in the scoop be x.

Thus,
`(x)/(25)=(80)/(500)`

`\therefore x=(25* 80)/(500)= 4`

Thus in the scooped marble, 4 marbles are expected to be green.