Question

There are 18 pieces of chalk. The ratio of chalk that is yellow to chalk that is not yellow is 1 to 2. How many pieces of chalk are yellow?

Answer 1

1:2...added = 3

1/3(18) = 18/3 = 6 (yellow chalk)
2/3(18) = 36/3 = 12 (not yellow)

so 6 pieces are yellow and 12 pieces are not

Answer 2

6 chalk are yellow and 12 pieces of chalk are not yellow