Question

Jerry 1/5 of his allowance on a book and 3/8 of the remainder of his allowance for $12.00. Calculate: A.Jerry's allowance B.The cost of the book C.The cost of the pen

Answer 1

Allowance = $24

Cost of book = $4.8

Cost of pen = $7.2

Explanation:

`Let \ his \ allowance\ be\ x\\\\(1)/(5) \ of \ x \ on\ books\\\\(3)/(8) \ of (4)/(5) \ of \ x\ on \ pen\\\\Balance \ in \ hand = 12`

`x = (1)/(5)x + ((3)/(8) * (4)/(5))x +12\\\\x = (1)/(5)x + (12)/(40) +12\\\\x =(1)/(5)x + (3)/(10) +12\\\\x - (1)/(5)x - (3)/(10) =12\\\\(10x - 2x -3x)/(10) = 12\\\\(5)/(10)x = 12\\\\5x = 12 * 10\\5x = 120\\x = 24`

`cost \ of \ book = (1)/(5) * x = (1)/(5) * 24 = 4.8\\\\cost \ of \ pen = (3)/(8) * (4)/(5) * x = (3)/(8) * (4)/(5) * 24 = 7.2`

Answer 2

What grade are you just asking no offense