Mathematics

Question

Mr. Abernathy bought a selection of wrenches for his shop and paid $78. He bought the same number of $1.50 and $2.50 wrenches, and half of that number of $4 wrenches. The number of $3 wrenches is one more than the number of $4 wrenches. How many of each did he buy?

2 Answer

  • Let the number of $1.50 wrenches be x,
    number of $2.50 wrenches = x
    number of $4 wrenches = x/2
    number of $3 wrenches = x/2 + 1

    amount paid for $1.50 wrenches = 1.5x
    amount paid for $2.50 wrenches = 2.5x
    amount paid for $4 wrenches = 4(x/2)
    = 2x
    amount paid for $3 wrenches = 3(x/2 + 1)
    = 1.5x + 3

    total amount paid = 1.5x + 2.5x + 2x + 1.5x + 3
    = 7.5x + 3
    7.5x + 3 = 78
    7.5x = 75
    x = 10

    number of $1.50 wrenches = x
    = 10
    number of $2.50 wrenches = x
    = 10
    number of $4 wrenches = x/2
    = 10/2
    = 5
    number of $3 wrenches = x/2 + 1
    = 10/2 + 1
    = 5 + 1
    = 6

    He bought 10 $1.50 wrenches, 10 $2.50 wrenches, 5 $4 wrenches and 6 $3 wrenches.
  • 10 10 5 and 6 is right !!!!!!! yay!!!!!