A train covered a certain distance at a uniform speed.

Let the speed of the train be x km/h and the time taken by train to travel the given distance be t hours and the distance to travel be d km.

We know that, Speed =

x =

Or, d = xt (i)

Using the information given in the question, we obtain

(x + 10) =

(x+10) (t-2) = d

Xt+10t-2x-20 = d

By using equation (i),

we obtain - 2x + 10t = 20 (ii)

(x-10) =

(x-10) (t+3) = d

Xt-10t+3x-30 = d

By using equation (i), we

obtain 3x - 10t = 30 (iii)

Adding equations (ii) and (iii),

we obtain x = 50

Using equation (ii), we

obtain ( - 2) × (50) + 10t = 20

- 100 + 10t =

10t = 120

t = 12 hours

From equation (i), we obtain

Distance to travel = d = xt

= 50 × 12

= 600 km

Hence, the distance covered by the train is 600 km.