A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km/hr, the time taken by it to cover the same distance will be :

Answer: Option B

Speed of the train :
= $$\frac{10\times 60}{12}$$
= 50 km/hr
Now, new speed :
= 50 - 5
= 45 km/hr
And, required time :
= $$\frac{10}{45}$$
= $$\frac{2}{9}$$ × 60
= 13 minutes 20 seconds