A, B and C started a business with their investments in the ratio 1 : 2 : 4 . After 6-month A invested the half amount more as before and B invested same the amount as before while C withdrew $$1\over 4$$th of the his investments. Find the ratio of their profits at the end of the year. 

If the ratio of two numbers is 13 : 15 and their L.C.M. is 39780. Then the numbers are?

A cyclist cycles 8 km at 15 km/hr and a further 4 km at 20 km/hr. Find the average speed in km/hr. 

Three bottles of equal capacity are containing a mixture of milk and water in ratio 1: 3, 3: 5 and 11: 5 respectively. These three bottles are emptied into a large bottle. What is the ratio of milk and water respectively in this large bottle?

Rs.4000 becomes Rs. 5000 in 4 years at a certain rate of compound interest. What will be the sum at the end of 12 years?

A, B and C gets a total wage of Rs.3600 if they work together. A and B gets a total wage of Rs. 2800 if they work together and A alone gets Rs.1600. Find the efficiency ratio of A, B and C