Which number is appropriate in place of question mark?

There are 3 green, 4 orange and 5 white colour bulbs in a bag. If a bulb is picked at random, what is the prob...

In the figure, AD and BC are lines intersecting at O. What is the value of a?

The tax on a commodity is diminished by 10% and its consumption increases by 10%. Find the effects on revenue.

There are two squares S and S The ratio of their areas is 4 : 25. If the side of S is 6 cm. What is the side o...

A is twice as good a workman as B and together they finish a piece of work in 1 day. A alone can finish the wo...

The average of two numbers is 62. If 2 is added to the smaller number, the ratio between the numbers becomes 1...