If the cost of painting 1 sq m is Rs.50, then what will be the maximum amount of saved in painting the room in the most economical way, if the sum of the length , breadth and height is 21 and all sides are integers? (floor is not painted ).

1 ) 10850
2) 8400
3) 9650
4) 8540

Question

If the cost of painting 1 sq m is Rs.50, then what will be the maximum amount of saved in painting the room in the most economical way, if the sum of the length , breadth and height is 21 and all sides are integers? (floor is not painted ).

1 ) 10850
2)  8400
3)  9650
4)  8540

anonymous · Answer

What's your guess?

anonymous · Answer

No clue.

hartnn · Answer

for the saved amount to be maximum,
lets consider the volume to be maximum.

Volume will be max when the room is cube-shaped.

length = height = breadth = 7 (since their sum= 21)

now try to calculate area of the faces, excluding floor

anonymous · Answer

Should't volume be the minimum to save the maximum ?

anonymous · Answer

And if I calculate like the way you suggested, the answer comes out to be Rs.12250

hartnn · Answer

how are we calculating saved amount here?

anonymous · Answer

No clue :/

hartnn · Answer

seems to be an incomplete question.

to find how much we saved,
we need to find how much we spent before...

hartnn · Answer

saved amt = amt spent before - amount spent now, when sum = 21