Question

i want thr answer to questian no. 17.

Answer 1

let l.b.h be 1x.2x.4x
let side of cube be x
volume of cuboid =volume of cube
1x×2x×4x=acube
8xcube=acube
a=2x
difference between their surface areas=total cost/rate
6a square-2 (2xsquare+8xsquare+4xsquare)=80/5
6 (2xsquare)-2(14xsquare)
=16
12xsquare-28xsquare
=16
16xsquare=16
so x=1
implies that..side of cube=2x
that is a=2
so volume of cube = volume of cuboid= a cube
2 cube
=8

Answer 2

Refer the image.

Hope it helps you!