A train starts from Mumbai towards Bengaluru at a speed of 80 kmph. After half an hour, another train from Bengaluru starts running towards Mumbai at a speed of 100 kmph. Find the distance travelled by the slower train when both the trains meet if the distance between Mumbai and Bengaluru is 940 kms.

In the first half an hour, the slower train covers some distance, which is 

$$80\times\dfrac{30}{60}=40\ $$ km

Hence, now the distance between the two trains is $$940-40\ =900$$ km.

The time after which both trains meet is $$\dfrac{900}{80+100}=\dfrac{900}{180}=5$$ hrs

Hence, the distance travelled in this time by the slower train will be $$5\times80=400$$ km

But it also covered 40 km before this, so the total distance travelled is 40+400 = 440 km.

Hence, the answer is 440 km.