Question

What is the time period of a pendulum which completes 42 oscillations in 20 seconds??​

Answer 1

No. of oscillations completed by the pendulum= 42 

Time taken to complete 42 oscillation= 20 seconds 

Time period= No. of oscillations completed/Time taken 

Time period= 42/20 

= 21/10 (cancelled by 2) 

= 2.1 

Time period= 2.1 seconds

Answer 2

42/20=time period=2.1s