Question 830044
Over a period of time of five days the average time of a commuter train trip from one town to the city was 77 minutes.
 One trip was 71 minutes, another was 74 minutes, and two were 78 minutes. How many minutes long was the fifth trip?
:
Let x = time of the 5th trip
{{{((x+71+74+78+78))/5}}} = 77
add the values, multiply both sides by 5
x + 301 = 5(77)
you should be able to do it now