A toothed wheel of diameter 50 cm is attached to a smaller wheel of diameter 30 cm. How many revolutions will the smaller wheel make when the larger one makes 30 revolutions?

A wheel makes 1000 revolutions in covering a distance of 88 km. Find the radius of the wheel.

If the length of a side of a square is same as length of the diameter of a circle, then the ratio of their areas is :

1. 1 : π

2. 2 : π

3. 4 : π

4. 8 : π

The ratio of the numerical values of the circumference and area of a semicircle of radius 5 units is :

1. 4 : 5

2. 2 : 5

3. 12 : 25

4. 6 : 25