David bought 3 fiction books. The original price of each fiction book was $50. He was given 25% discount on the first fiction book and 30% discount on the rest of the fiction books. How much did he pay for the 3 fiction books altogether?
Cost of the first fiction book after 25% discount in percent
= 100% - 25%
= 75%

Cost of the first fiction book after discount
= 75% x 50
= ⁷⁵₁₀₀ x 50
= $37.50

Number of the rest of the fiction books that enjoyed 30% discount
= 3 - 1
= 2

Cost of each of the rest of the 2 fiction books after 30% discount in percent
= 100% - 30%
= 70%

Cost of each of the rest of the 2 fiction books
= 70% x 50
= ⁷⁰₁₀₀ x 50
= $35

Cost of the rest of the 2 fiction books that enjoyed 30% discount
= 2 x 35 
= $70

Total cost for the 3 fiction books
= 37.50 + 70
= $107.50

Answer(s): $107.50