If 9 engines consume 24 metric tonnes of coal, when each is working 8 hours
day, how much coal will be required for 8 engines, each running 13hours a day, it being given that 3 engines of former type consume as much as 4 engines of latter type?	Choose the most appropriate option
A) 23 metric tonnes B) 24 metric tonnes C) 25 metric tonnes D) 26 metric tonnes E) 27 metric tonnes
We shall compare each item with the quantity of coal.   Less engines, less coal consumed (direct)   More working hours, more coal consumed (direct)   If 3 engines of former type consume 1 unit, then 1 engine will consume 1/3 unit.   If 4 engines of latter type consume 1 unit, then 1 engine will consume 1/4 unit.   Less rate of consumption, less coal consumed (direct).   Therefore, number of engines 9:8 :: 24:x   Working hours 8:13 :: 24:x   Rate of consumption 1/3:1/4 :: 24:x.   9*8*1/3*x= 8*13*1/4*24 or x= 26.   Therefore, required consumption of coal 26 metric tonnes.   ANSWER:26 metric tonnes
<result>D</result>
If 9 engines consume 24 metric tonnes of coal, when each is working 8 hours
day, how much coal will be required for 8 engines, each running 13hours a day, it being given that 3 engines of former type consume as much as 4 engines of latter type?