Answer:
120 labourers.
Explanation:
The question is to determine the number of workers employed by the plant
The following steps are undertaken
a) If the annual output of water heaters is 57,600, it means the monthly output = 57,600/ 12 months = 4,800 water heaters per month
b) since the labour hours of each worker is 160 hours per month, then we use the following formula to substitute and know the number of labourers
Let the number of labourers be x.
This means that 160x hours per month = x number of labourers
= Labour input = 160x hours per month
If labour productivity = 0.25;
then, Labour productivity = Output per month /labor input
= 0.25= 4800 heaters/ 160x
= 25/100 = 4800/160x
= 160x = 4800 x 100) ÷ 25
= 160x = 19,200
= 19200/160 = x
120 = x
The plant employed 120 labourers.