The number of calculators
= Number of boxes * calculators in each box
=18* 12
= 216 calculators
{8, 16, 24, 32}int.{16, 32, 48}={16, 32}
The equation to model this would be 65 = 11r + 9s.
In this equation, we know that the total number he works is 65. We also know he burns 11 every time he runs for an hour. Therefore we can multiply 11 by r. We also know he burns 9 for every hour he spends swimming. Therefore we can multiply 9 by s.
When we put all three of these things together, we get 65 = 11r + 9s.
