Question

25 a bus travels a certain distance taking 7 hrs. In forward journey, during the return journey increased speed by 12km/hr. Takes the times 5 hrs. What is the distance travelled by the bus

Answer 1

let speed be x.
so, by formula
D = ST (D for distance , S for speed , T for time)
D1 = 7x. -----------(statement 1)

now for return journey
Given, In return journey speed increased by12kmph.
means , 12 + x (x is forward journey speed)
time taken by car while returning back 5hrs
so,
D2 = ST
D2 = (x+12)*5
D2 = 5x+60 -----------(statement 2)

from statement 1 & statement 2
one thing is clear that in between distance of forward journey & retuning journey is same.
whatever distance dist. cover by car in forward journey is as same as covered in backward journey.

what we get,
5x+60 = 7x
60 = 2x
x = 30