Book a has 24 more pages than book b. book c has 4 times as many pages as book a. the total number of pages of pages of the three books is 180. how many pages does book b have?

A = 24 + b
c = 4a = 4(24 +b) = 96 + 4b
b =b
a + b + c = 180
24 + b + b + 96 + 4b = 180
Combine the variables and the whole numbers: 
120 + 6b = 180
-120           -120
6b = 60
divide on both sides by 6, and b=10
b = 10 a = 34 c = 136, 10 + 34 + 136 = 180