A man invested certain amount of money in two schemes A and B which offer interest at the rate of 8% per annum and 9% per annum respectivley. He received ₹ 1,860 as annual interest. However, if he had interchanged the amount of investments in the two schemes, he would have received ₹ 20 more as annual interest. How much money did he invest in each scheme ?

3 men and 4 boys can do a piece of work in 14 days, while 4 men and 6 boys can do it in 10 days. How long would it take 1 boy to finish the work ?

A train leaves New Delhi for Ludhiana, 324 km away, at 9 a.m. One hour later, another train leaves Ludhiana for New Delhi. They meet at noon. If the second train had started at 9 a.m. and the first train at 10.30 am., they both would still have met at noon. Find the speed of each train.