You can rent a bicycle for $12 per hour, or buy a new one for $99. How many hours do you need to ride for the cost of buying the bicycle to be cheaper than renting it?

The correct answer is: We need to ride more than 8.25 hours or 8 hours & 15 minutes for the cost of buying the bicycle to be cheaper than renting it

Hint:-
Total cost of renting = number of hours * Rate per hour.
Step-by-step solution:-
Let the number of hours, the bicycle is to be ridden be x.
∴ Total cost incurred for renting = Number of hours * cost per hour
∴ Total cost incurred for renting = x * $12 ..................................................... (From given information)
∴ Total cost incurred for renting = 12x ........................................................... (Equation i)
Also,
Total cost incurred on buying = $99 .................... (From given information) ............................. (Equation ii)
We need to find the number of hours, the bicycle is to be ridden to make the cost of buying cheaper than renting.
i.e. we need to find the value of x for which-
Cost incurred on renting > Cost incurred on buying
∴ 12x > 99 ...................................................................................... (From Equations i & ii)
∴ x > 99/12 .................................................................................. (Dividing both sides by 12)
∴ x > 8.25 or 8 hours & 15 minutes ........................................... (1 hour = 60 min.)
Final Answer:-
∴ We need to ride more than 8.25 hours or 8 hours & 15 minutes for the cost of buying the bicycle to be cheaper than renting it.