A factory is operating in two shifts, day and night, with 70 and 30 workers respectively. If per day mean wage of the day shift workers is Rs.54 and per day mean wage of all the workers is Rs.60, then per day mean wage of the night shift workers (in Rs) is :

Question

$\begin{array}{1 1} 66 \\ 69 \\ 74 \\ 75 \end{array}$