Question
The volume of a rectangular block of stone is 10368 `dm^3`. Its dimensions are in he ratio of 3 : 2 : 1 . If its entire surface is polished at 2 paise per `dm^2`, then the total cost will be :
Answer: Option D
Was this answer helpful ?
Let the dimensions be `3x, 2x, and x` respectively , Then ,
`3x xx 2x xx x = 10368`
`hArr 6x^3 = 10368` `hArr x^3 = (10368/6) hArr x ^3 = 1728 hArr x = 12`
So, the dimensuions of the block are 36 dm, 24 dm, and 12 dm.
Surface area = [2 ( 36 x 24 + 24 x 12 + 36 x 12)] `dm^2`
= [2 x 144(6 + 2 + 3)] `dm^2` = 3168 `dm^2`
`:.` Cost of polishing = Rs.` ((2 xx 3168)/(100))` = Rs. 63.36 .
Was this answer helpful ?
More Questions on This Topic :
Latest Videos
Latest Test Papers
Submit Solution