A and B together can complete a particular task in 6 days. If A alone can complete the same task in 10 days, how many days will B take tocomplete the task if he works alone?

2,40,000 is taken as loan for three years compounded annually at 12.5 % p.a. At the end of first year, the interest is revised to 12 % p.a. The total amount to be repaid at the end of third year is:

Two students appeared at an examination. One of them secured 9 marks more than the other and his marks were 56 % of the sum of their marks. The marks obtained by them are: 

A, B and C start running around a circular field having circumference 144 metre at the same time from the same point. Speeds of A, B and C are 6 m/minute, 8 m/minute and 12 m/minute. Find after how much time, they will meet again at the same point for the first time.

The centroid of a ∆ABC is G. The area of ∆ABC is 60 cm². The area of ∆GBC is

A person lends 40 % of his sum of money at 15 % per annum, 50 % of rest at 10 % per annum and the rest at 18 % per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum? 

In what time will ₹ 64,000 amount to ₹ 68,921 at 5 % per annum interest being compounded half yearly? 

The average of seven numbers is 18. If one of the number is 17 and if it is replaced by 31, then the average becomes: