If 10 men or 20 women or 40 children can do a piece of work in 7 days, then 5 men, 5 women and 5 children together can do half of the work in 

The 3rd and 8th term of an arithmetic  progression are 19 and 49 respectively. What is the 13th term?

The ratio of the present age of P and Q is 2: 3. The ratio of their age after 18 years will be 4: 5. What is the present age of Q?

A DVD player was purchased for Rs 4860. At what price should it be sold so that 25% profit is earned?

A motor car finishes a journey in 10 hours. The first half at 21 km/hr. and the rest at 24 km/hr. Find the distance?

 A principal of Rs. 6120 becomes Rs. 8330 in 2 years when compounded annually at some rate of interest. How much will be the amount if the same principal was compounded half-yearly?

 ₹ 800 becomes ₹ 956 in 3 years at a certain rate of simple interest. If the rate of interest is increased by 4 %, what amount will ₹ 800 become in 3 years?