The average of ten numbers is 72. The average of the first four numbers is 69 and that of the next three number is 74. The 8^th number is 6 more than the 9^th number and 12 more than the 10^th number. What is the average of the 8^th and 9^th numbers?

A can complete a piece of work in 18 days, B in 20 days and C in 30 days. B and C together start the work and are forced to leave after 2 days. The time taken by A alone to complete the remaining work is?

There is a loss of 5% by selling an article for Rs.665. In order to get 12% profit on that article, its selling price has to be kept?

Directions:  The table given below presents the number of books on different subjects kept on separate shelves subjects with odd and even numbers are of arts and Science respectively

The number of books of S2 is what percent of number of books of S6?

A line touches a circle of a radius 6 cm. Another line is drawn which is tangent to the circle. If the two lines are parallel then the distance between them is:

A person can hit a target 5 times out of 8 shots. If he fires 10 shots, what is the probability that he will the target twice?

What number must be subtracted from each of the numbers 55, 23, 43 and 19, so that the new values are in proportion? 

The number which can be written in the form of n (n+1) (n+2), where n is a natural number, is: