Question:
The short and long hands of a clock are 4 cm and 6 cm long respectively. Find the sum of distances travelled by their tips in 2 days.
Solution:
In 2 days, the short hand will complete 4 rounds.
Length of the short hand = 4 cm
Distance covered by the short hand $=4 \times 2 \pi \times 4=32 \pi \mathrm{cm}$
In the same 2 days, the long hand will complete 48 rounds.
Length of the long hand = 6 cm
Distance covered by the long hand $=48 \times 2 \pi \times 6=576 \pi \mathrm{cm}$
∴ Total distance covered by both the hands = Distance covered by the short hand + Distance covered by the long hand
$=32 \pi+576 \pi$
$=608 \pi$
$=608 \times 3.14$
$=1909.12 \mathrm{~cm}$