Question

A salesman sold 200 pairs of slippers. Some were sold at $6 per pair and the remainder were sold at $11 per pair. Total receipts from this sale were $1600. How many pairs of slippers were sold at $6 each?

Answer 1

Solution.

Let the number of pairs sold at $6 per pair be x

Let the number of pairs sold at $11 per pair be y

`\begin{gathered} x+y=200-------(1) \\ 6x+11y=1600------(2) \end{gathered}`
`\begin{gathered} Multiply\text{ equation \lparen1\rparen by 11} \\ 11x+11y=2200 \\ 6x+11y=1600 \end{gathered}`
`\begin{gathered} Subtract\text{ both equations} \\ 11x-6x=600 \\ 5x=600 \\ x=(600)/(5) \\ x=120 \end{gathered}`

Thus, the number of pairs of slippers sold at $6 each is 120