Distance, Rate and Time Question

Question

Tom Quig traveled 250 miles east of St. Louis. For mot of the trip, he averaged 70 mph but for one period of time, he was slowed to 10 mph due to a major accident. If the total time of travel was 7 hours, how long did he drive at the reduced speed?

Answer 1

t=time at reduced speed

70×(7-t)+10t=250

490-70t+10t=250

240=60t

t=4

N.B. 70×3+10×4=250