Can you guess

Nancy drives to the school to pick up her children. If she drives at her current speed, she will arrive on time. If she drives 5 miles per hour faster, she will arrive 12 minutes early. If she were to drive 5 miles per hour slower instead, she would arrive 15 minutes late.
Can you guess how far away the school is?

We all know that time = distance/speed
If the original time is t then we are given that
Distance/(speed+5) = time – 12/60 = time – .2
Distance/(speed-5) = time + 15/60 = time + .5

Solving this we get
Distance = 90

Am I right!!!!!!!!!!!