A sum of money of Rs. 1000 is lent out in two parts in such a way that the interest on one part at 10% per annum for 5 years is equal to another at 5% for 10 years. Calculate the sum lent out at 5%.
Two trains are moving in the same direction at the speed of 23 km/hr and 77 km/hr. The time taken by faster train to cross a man sitting in the slower train is 40 seconds. What will be the length (in metres) of the faster train?