Train completes journey of 150 miles one hour earlier if original speed is increased by 5mes/hour what is original speed

25mph.

using the equation distance = speed x time, you can make 2 equations. let x be the original speed of the train, and t be the original time it takes. the first equation is the original trip, the 2nd is your new speed and shortened time.

this is because you are adding 5mph, and taking off 1 hour of time, to still cover the 150 miles. you can solve the first equation for t, and substitute into the second, and then solve for x.

and using the quadratic formula you can find x=25.