Question

A patrolman gives a driver a speeding ticket if the driver’s speed is greater than 15% over the posted speed limit. If the speed limit is 40 miles per hour, what is the highest speed that a driver can go without receiving a ticket?

Answer 1

The driver can drive at 46 mph.

Explanation:

A patrolman gives a driver a speeding ticket if the driver’s speed is greater than 15% over the posted speed limit.

If the speed limit is x, if the driver is driving greater than 1.15x, they will receive a speeding ticket.

Replace x with 40.

If the speed limit is 40, if the driver is driving greater than 1.15*40, they will receive a speeding ticket. Therefore, If the driver is driving greater than 46, they will receive a speeding ticket.

As it states "greater" and not "greater than or equal to", the driver can drive at 46 mph.