SOLUTION: A 810-mile, 7-hour plane trip was flown at two speeds. For the first part of the trip, the average speed was 111 mph. For the remainder of the trip, the average speed was 122 mph.

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Question 1196999: A 810-mile, 7-hour plane trip was flown at two speeds. For the first part of the trip, the average speed was 111 mph. For the remainder of the trip, the average speed was 122 mph. How long (in hours) did the plane fly at each speed?

111 mph=____Hr.?
122 mph=____HR?
Found 2 solutions by ewatrrr, josgarithmetic:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!

Hi  
A 810-mile, 7-hour plane trip was flown at two speeds: 111mph & 122mph
How long (in hours) did the plane fly at each speed?
Let x represent speed at 122mph
111(7hr-x) + 122x = 810mi
          11x = 810 - 7(111)
          11x = 33mi  
            x = 3hr, time flown at 122mph  &   4hr at 111mph
Checking our work:
 366mi + 444mi = 810mi checks
  Wish You the Best in your Studies.


Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
A D mile, T hour plane trip was flown at two speeds. For the first part of the trip,
the average speed was L mph. For the remainder of the trip, the average speed was G mph.
How long (in hours) did the plane fly at each speed? 

               SPEEDS         TIMES       DISTANCES

LOWER SPEED       L             T-x        L(T-x)

GREATER SPD.      G              x         Gx

TOTAL                            T           D

highlight_green%28L%28T-x%29%2BGx=D%29

LT-Lx%2BGx=D
%28G-L%29x%2BLT=D
%28G-L%29x=D-LT
highlight_green%28x=%28D-LT%29%2F%28G-L%29%29

Your example gives
D=810
L=111
G=122
T=7

Substitute and evaluate the unknown time, x.
Use it to evaluate T-x.