An Unusual Purchase

Strategies and Hints

  1. n + h + t  = 100
    n + 10h + 50t  = 500

  2. The replacement set for the variables is the set of whole numbers. Negative or fractional answers would not make sense in the problem context.

  3. The problem might appear impossible to solve because there are three unknowns and only two equations.

  4. Subtracting n + h + t  = 100 from n + 10h + 50t  = 500 results in 9h + 49t  = 400. This can be written as

h = 44 - 5t +

This form of the equation helps you find those values of t which will result in h being a whole number.

Solution

t = 1 is the only integral value of t that makes sense in h = 44 - 5t +

So, t = 1, h = 39, and n = 60. The customer bought 1 roll of electrical tape, 39 hooks, and 60 nails.