Assertion (A): Total surface area of semi-circle is 18.48 cm². Its radius is 14 cm.

Reason (R): Total surface area of a semi-circle of radius r is given by 2πr².

1. A is true, R is false

2. A is false, R is true

3. Both A and R are true

4. Both A and R are false

Assertion (A): The diameter of a cycle wheel is 21 cm. It will make 2000 revolutions to cover a distance of 1.32 km.

Reason (R): Distance covered by a wheel of radius r in one revolution is given by 2πr.

1. A is true, R is false

2. A is false, R is true

3. Both A and R are true

4. Both A and R are false

Four circular cardboard pieces, each of radius 7 cm are placed in such a way that each piece touches two other pieces. The area of the space enclosed by the four pieces is :

1. 42 cm²

2. 40 cm²

3. 21 cm²

4. 18 cm²

In the figure, if the radius of each circle is 5 cm, then area of the shaded region is :

1. (400 - 50π) cm²

2. (400 + 100π) cm²

3. (400 - 100π) cm²

4. 231 cm²