Two coal loading machines each working 12 hours per day for 8 days handles 9,000 tonnes of coal with an efficiency of 90%. While 3 other coal loading machines at an efficiency of 80% set to handle 12,000 tonnes of coal in 6 days. Find how many hours per day each should work.
More machines, less hours (Indirect Proportion)
Less days, more hours (Indirect Proportion)
More amount of coal, more hours (Direct Proportion)
Less efficiency, more hours (Indirect Proportion)
⇒ 3 × 6 × 9,000 × 0.8 × x
= 2 × 8 × 12,000 × 0.9× 12
⇒ x = 16 hrs