Discussion

Explanation:

The time taken by the white spots on all three wheels to simultaneously touch the ground again will be equal to the LCM of the times taken by the three wheels to complete one revolution.
The first wheel complete 60 revolutions per minute.

This means that to complete one revolution, it takes $\left(\frac{60}{60}\right)$ = 1 s.

Similarly, the second wheel takes $\left(\frac{36}{60}\right)=\frac{3}{5}$ s to complete one revolution.
Similarly, the third wheel takes $\frac{24}{60}=\frac{2}{5}$ s to complete one revolution.
Hence, LCM of 1, $\frac{3}{5},\frac{2}{5}=\frac{L.C.M. (1,3,2)}{H.C.F. (1,5,5)}=\frac{6}{1}=6$ s

» Your doubt will be displayed only after approval.