# Question #70ea8

We know that the frequency $\left(n\right)$ of a wave is defined as the number of waves formed per sec and its time period $\left(T\right)$ is the time taken to form a wave.
So $T = \frac{1}{n}$
In the given problem $n = 3 H z$
So time period $T = \frac{1}{n} = \frac{1}{3} s$