1. We can simply multiply 6.50 by 2!
6.50 x 2 = 13
The book cost $13
2. The easiest way to do this is to convert the fractions into decimals.
1/4 = 0.25
1/5 = 0.2
1/8 = 0.125
Add them together: 0.575!
Subtract this from 1: .425
Multiply by 100: 42.5
42.5% is your answer!
Hope this helps!