Question

The hour and minute hands of a clock are 4.2 cm and 7 cm long respectively. The sum of the diameter covered by their tips in 1 day is _____ (in cm).

Answer 1

An hour hand completes 2 rotations in 1 day i.e, in 24 hours.

Therefore, distance covered by the hour hand in 1 day = $2\times circumference=2\times 2\pi r$

$=2\times 2\times \frac{22}{7}\times 4.2cm$

$=52.8cm$

Minute hand completes 24 rotations in 1 day.

Therefore, distance covered by the minute hand in 1 day

$=24\times circumference$

$=24\times 2\times \frac{22}{7}\times 7=1056cm$

Therefore,

Sum of the distance covered by the tips of two hands =$52.8+1056=1108.8cm$