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

The radius of a circle whose area is equal to the sum of the areas of two circles of radii 7 cm and 24 cm respectively is :

1. 31 cm

2. 28 cm

3. 27 cm

4. 25 cm