Business trip of 325.5 miles. averaged 49 mph for the first part of the trip and 58 mph for the second part. if the trip took 6 hrs, how long was traveled?

Let t = travel time at 58

and

(6-t) = travel time at 49

distance at 58 + distance at 49 = 325.5 mi

58t + 49(6-t) = 325.5
58t + 294 - 49t = 325.5

9t+294 = 325.5

9t =31.5

T = 31.5/9 = 3.5 hours at 58 mph

6-3.5 = 2.5 hours at 49 mph

 Check:

58*3.5 = 203

49*2.5= 122.5

203+122.5 = 325.5

14.4%

L*W*H=V=10*9*4.5=405 in^3.

that is 50.5 in^3 over the estimate, or 14.4%