Question -
Answer -
Total journey = 150 km
Let the usual speed of the train = x km/hr
According to the condition,
┬а
=> x (x + 30) тАУ 25 (x + 30) = 0
=> (x + 30) (x тАУ 25) = 0
Either x + 30 = 0, then x = -30 but it is not possible being negative
or x тАУ 25 = 0, then x = 25
Usual speed of the train = 25 km/hr