Question

Maggie has a box of 200 colored blocks. The box has an equal number of green and blue blocks and an equal number of red and yellow blocks. If Maggie arranged all of the green blocks in stacks of 10 and all of the blue blocks in stacks of 7, how many yellow blocks are in the box?

A) 15
B) 20
C) 25
D) 30

Answer 1

It's D) 30.
The first common multiple of 10 and 7 is 70, so we know there are either 70 or 140 blue and green blocks. It must be 140 or there would be an option of 65. 200-140=60. Because there is the same amount of red blocks, it is split into two parts. 60/2=30.

Hope this helps you:)