A sum of money becomes Rs 16000 in 6 years at the rate of 25% per annum simple interest. What is the total interest for 6 years?

In 5 years, the simple interest on an amount of Rs. X is $$2\over 5$$ of the principal. The rate of interest per annum is:

Two towns P and Q are 170 km apart, a train starts at 9 a.m. from P towards Q at a speed of 40 km/hr, at 11 a.m. another train starts from Q towards P at a speed of 50 km/hr. When will the two trains meet?

The breadth ‘b’ of a room is twice its height and half of its length. Find the length of the longest diagonal of the room.

What is the value of $${{0.6}÷{0.6}×{0.6}+{0.5}×{0.5}÷{0.5}\over{0.6}×{0.5}+{0.3}}$$ ?

The following table shows the number of laptops sold from five different stores in a city on five days of a given week.

What is the ratio of the total number of computers sold from store S on Tuesday, Monday and Sunday taken together to that sold from store P on Tuesday, Wednesday and Thursday taken together?

There is a profit of 10% when an item is sold at $${{5\over6}}$$ of its actual selling price. What will be the profit percentage on the cost price when the item is sold at its actual selling price?

A money-lender borrows money at 4% per annum and pays the interest at the end of the year. He lends it at 6% per annum compound interest compounded half yearly and receives the interest at the end of the year. In this way; he ghins Rs. 104.50 a year. The amount of money he borrows, is: