Question

Two coal loading machines, each working 12 h per day for 8 days, handle 9000 tonne of coal with an 1 efficiency of 90%, while 3 other coal loading machines at an efficiency of 80% are set to handle 12000 tonne of coal in 6 days. How many hours per day should each machine work?

• A. 18 h per day
• B. 16 h per day
• C. 20 h per day
• D. 14 h per day

Answer 1

Answer: (B)

16 h per day

Answer 2

According to the question,

time $\frac{time 1}{amount of work done 1}=\frac{time 2}{amount of work done 2}$

(12$\times$8$\times$.9):$(\frac{9000}{2})$::(6x$\times$.8):$(\frac{12000}{3})$

So, on solving , we get

x $=\frac{16hr}{day}$...
So the correct option is (B)