Ivan bought 4 fiction books. The original price of each fiction book was $30. 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 4 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 30
= ⁷⁵₁₀₀ x 30
= $22.50

Number of the rest of the fiction books that enjoyed 30% discount
= 4 - 1
= 3

Cost of each of the rest of the 3 fiction books after 30% discount in percent
= 100% - 30%
= 70%

Cost of each of the rest of the 3 fiction books
= 70% x 30
= ⁷⁰₁₀₀ x 30
= $21

Cost of the rest of the 3 fiction books that enjoyed 30% discount
= 3 x 21 
= $63

Total cost for the 4 fiction books
= 22.50 + 63
= $85.50

Answer(s): $85.50