A boy has 40 red and blue pencils in his pencil case. If the ratio of red to blue pencils is 0.15 to 0.35, how many blue pencils does he have?

The boy has 28 blue pencils

Step-by-step explanation:

Given

Total pencils = 40

The ratio of red to blue = 0.15:0.35

We have to find the number of blue pencils

For that we need the sum of ratio = 0.15+0.35 = 0.5

So, the number of blue pencils = (ratio of blue/sum of ratio) * total pencils

=0.35/0.5 * 40

=0.7*40

=28 pencils

Therefore, the boy has 28 blue pencils ...