gabriella rents bikes for $13 plus $7 per hour. Eduardo paid $27 to rent a bike for how many hours did he rent the bike?

He has it for 2 hours

The total cost was $27. The total cost is made up of a fixed amount, $13, and an hourly amount. Subtract the fixed amount from the total cost to find the hourly amount.

$27 - $13 = $14

$27 = total cost

$13 = fixed cost

$14 = hourly cost

Since the hourly rate is $7/hour,

$14 / ($7/hr) = 2 hours

He rented for 2 hours.