Question

a motorist left a city for a 295 mile. 7 hour trip. for the first part of the trip, the average speed was 40mph. for the remainder of the trip, the average speed was 55mph. How long did the motorist drive 55mph

Answer 1

time of first leg --- x hrs
time of 2nd leg --- 7-x hrs

solve for x, then sub into 7-x

40x + 55(7-x) = 295