If the diameter of a car tyre is 56 cm, then:

(A) How far does the car need to travel for the tyre to complete one revolution?

(B) How many revolutions does the tyre make if the car travels 10 km?                                  [Page No. 130]

(A) $\text{Distance} = \text{Circumference} = \pi d$

$$= \frac{22}{7} \times 56 = 22 \times 8$$

$$= 176 \text{ cm} = 1.76 \text{ m}$$

(B) Number of revolutions = $\frac{\text{Total distance}}{\text{Circumference}}$

$$= \frac{10000 \text{ m}}{1.76 \text{ m}} = 5,681.82 \text{ revolutions}$$

$$= 5,682 \text{ revolutions (approx)}$$