The number of accidents for seven days in a locality are given below:No. of accidents | $\displaystyle 0$ | $\displaystyle 1$ | $\displaystyle 2$ | $\displaystyle 3$ | $\displaystyle 4$ | $\displaystyle 5$ | $\displaystyle 6$Frequency | $\displaystyle 15$ | $\displaystyle 25$ | $\displaystyle 30$ | $\displaystyle 9$ | $\displaystyle 3$ | $\displaystyle 2$ | $\displaystyle 1$What is the number of cases when $\displaystyle 3$ or less accidents occurred?