26. Statistics question bank (Maths)

The mean of the data comprising of 16 observations is 16. If one of the observations valued 16 is deleted and three new observations valued 3, 4 and 5 are added to the data, then the mean of the resultant data is 

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 ₹54 and per day mean wage of all the workers is ₹60, then per day mean wage of the night shift workers (in ₹) is