If 9 engines consume 24 metric tonnes of coal, when each is working 8 hours day, bow 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 correct choice from the following options.
A) 24 metric tonnes	B) 36 metric tonnes	C) 14 metric tonnes	D) 43 metric tonnes	E) 26 metric tonnes
Let 3 engines of former type consume 1 unit in 1 hour.   Then, 4 engines of latter type consume 1 unit in 1 hour.   Therefore 1 engine of former type consumes(1/3) unit in 1 hour.   1 engine of latter type consumes(1/4) unit in 1 hour.   Let the required consumption of coal be x units.   Less engines, Less coal consumed (direct proportion)   More working hours, More coal consumed (direct proportion)   Less rate of consumption, Less coal consumed(direct prportion)   Number of engines 9: 8   Working hours	8 : 13 } :: 24 : x   Rate of consumption (1/3):(1/4)   [ 9 x 8 x (1/3) x x) = (8 x 13 x (1/4) x 24 )   24x = 624   x = 26.   Hence, the required consumption of coal = 26 metric tonnes.   Answer is 26 metric tonnes.
<result>E</result>
If 9 engines consume 24 metric tonnes of coal, when each is working 8 hours day, bow 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?