Correct Answer - Option 1 : 41 kmph

**Given:**

Distance between Delhi to Bangalore = 1230 km

Difference between times for travelling by train and flight = 10 hrs.

**Formula Used:**

Speed = Distance/Time

**Calculations:**

Let the speed of train and flight be x kmph and y kmph respectively.

(1230/x) – (1230/y) = 10 ----(1)

When speed of train becomes thrice

(1230/y) – (1230/3x) = 10 ----(2)

Adding (1) and (2), we get

⇒ (1230/x) – (1230/3x) = 20

⇒ 1230 × (2/3x) = 20

⇒ x = 1230 × (2/3) × (1/20)

⇒ x = 41 kmph

**∴ The speed of train is 41 kmph.**