Toby is filling his swimming pool for the summer. The pool normally takes 50 hours to fill. He knows his hose runs at 100 gallons per hour. Water costs 1 cent for 10 gallons. How many dollars does it cost to fill the pool?
Think hard. Detailed solution:
5
The pool holds 5000 gallons of water because 50 x 100 = 5000.

Every gallon costs $.

001 because $.

01 / 10 = $.

001.

It costs $5 to fill the pool because 5000 x $.

001 = $5.

.

Thus, the answer is 5