Problem Solving

Question

Tom's Lego people have either black, brown or red hair.

2/5 have black hair. 1/7 have brown hair 64 people have red hair.

How many people have black hair?

Hiw many people have brown hair?

Answer 1

Hi Kelly,

The easiest way to solve Tom's MiniFig dilemma is to make a chart with what you know:

Black Brown Red

2/5 1/7 ? but has to be 1 - 2/5 - 1/7

x Y 64 total minifigs

You can't add or subtract fractions with different denominators, so convert them to 35th (5x7), so he has 14/35 black, 5/35 brown, and therefore 35/35 - 14/35 black - 5/35 brown to find the fraction of red. BUT you know that this fraction of red = 64, SO you can use that to to figure out the other numbers!