Question

Helen pulls one marble out of the box at random, records its color, replaces it, and mixes up the marbles again. If she does this 200 times, how many blue marbles should she excpect to pull out?

1/2 of the marbles are yellow
1/8 of the marbles are red
The rest of the marbles are blue

Answer 1

The answer to your problem is, 75

Explanation:

Yellow =
`(1)/(2)` of the marbles

Red =
`(1)/(8)` of the marbles

Blue =
`1 - (1)/(2) - (1)/(8) = (1)/(2) - (1)/(8)`

=
`(1*4)/(2*4) - (1)/(8)`

=
`(1)/(2) or (4)/(8) - (1)/(8)`

=
`(3)/(8)`

`(3)/(8)` of the marbles are represented as blue.

200 x
`(3)/(8)` = 25 x 3 = 75

Thus the answer to your problem is, 75