An animal shelter spends $3.00 per day to care for each cat and $5.00 per day to care for each dog. Penelope noticed that the shelter spent $69.00 caring for cats and dogs on Tuesday. Penelope found a record showing that there were a total of 17 cats and dogs on Tuesday. How many cats were at the shelter on Tuesday?
Let the number of cats = x
Then the number of dogs = 17 - x
And we have this
cost of care per cat * number + cost of care per dog * number = total revenue
3x + 5 (17 - x) = 69 simplify
3x + 85 - 5x = 69
-2x + 85 = 69 subtract 85 from both sides
-2x = -16 divide both sides by - 2
x = 8 (cats)