SOLUTION: The total cost of a pen and a book is $32. The cost of the pen is 3/5 the cost of the book. What is the cost of the book?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: The total cost of a pen and a book is $32. The cost of the pen is 3/5 the cost of the book. What is the cost of the book?      Log On


   

Question 1184387: The total cost of a pen and a book is $32. The cost of the pen is 3/5 the cost of
the book. What is the cost of the book?
Found 2 solutions by josgarithmetic, MathLover1:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Not something that would require asking for help.

%283%2F5%29b%2Bb=32
3b%2B5b=5%2A32
8b=160
highlight%28b=20%29

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!


let the cost of the pen be p and the cost of the book b
if the total cost of a pen and a book is $32, we have
p%2Bb=32.........eq.1
if the cost of the pen is 3%2F5 the cost of the book, we have
p=%283%2F5%29b..........eq.2
substitute p in eq.1
%283%2F5%29b%2Bb=32.........eq.1
%288%2F5%29b=32
b=%2832%2A5%29%2F8....simplify
b=4%2A5
b=20
then
p=%283%2F5%2920
p=%283%2F1%294
p=12
the cost of the book is $20+