On a rainy day, every kid at Margo's school brings a raincoat, an umbrella, or both. 8% of the kids bring both. The total number of kids with umbrellas is twice the total number of kids with raincoats.
What percent of the kids bring only an umbrella?
For simplicity, let's suppose that there are 100 kids at the school
If 8% bring both, then 8 bring both
Let the number who bring raincoats = x
Let the number who bring umbrellas = 2x
So....the ones that bring only raincoats = x - 8
And the ones that bring only umbrellas = 2x - 8
So......we have this equation
Kids who bring only umbrellas + kids who bring both + kids who only bring raincoats = 100
(2x -8) + 8 + (x - 8) = 100 simplify
3x - 8 = 100 add 8 to both sides
3x = 108 divide both sides by 3
x = 36
So....the ones who bring only a rain coat = 36 - 8 = 28
And the ones who bring only an umbrella = 2(36) - 8 = 72 - 8 = 64 = 64%
Check
Only umbrellas + Both + Only Raincoats = 100 ???
64 + 8 + 28 = 100 (Check)