[Q.1] What is the compound interest on Rs. 10,000 for 2 years at 10% per annum, compounded annually?
Amount = 10000 * (1.$10)^2$ = Rs. 12,100. CI = 12100 - 10000 = Rs. 2,100.
[Q.2] A train 150 meters long passes a telegraph pole in 15 seconds. What is the speed of the train in km/h?
Speed = 150 m / 15 s = 10 m/s. Convert to km/h: 10 * (18/5) = 36 km/h.
[Q.3] If the ratio of two numbers is 3 : 4 and their HCF is 4, what is their LCM?
Numbers are 3*4 = 12 and 4*4 = 16. LCM(12, 16) = 48.
[Q.4] A trader buys an article for Rs. 800 and sells it for Rs. 1,000. Find his profit percentage.
Profit = 1000 - 800 = 200. Profit % = (200 / 800) * 100 = 25%.
[Q.5] A and B can complete a work in 12 days and 16 days respectively. Working together, in how many days can they finish the work?
Combined rate = 1/12 + 1/16 = 7/48 work per day. Total time = 48/7 days.