CBSE Class 10 Answered
The problem is not specified correctly, if the speed is increased the train would arrive BEFORE the scheduled time, and won't take 6 hrs more but less. Also the information is not sufficient.
Let the uniform speed be U and time required is T, then the distance is UT.
If (U + 6) then we had T - 6
but the distance would be same,
(U+6)(T-6) = UT
UT + 6T - 6U - 36 = UT
6T - 6U = 36
T - U = 6