Question

If every side of a cuboid is increased to k times of its original, then the surface
area of the new cuboid will become ..... times the original surface area.
(A) 2k²
(B) 4k
(C) k^2
(D) (k+2)
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Answer 1

Answer:

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Step-by-step explanation:

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Answer 2

Answer:

k²is the answer which is option'c'

Step-by-step explanation:

let the surface area be x

let

length=l

breath=b

height=h

surface area of cuboid formula=2(lb+lh+bh)

a.t.q sides are increased by k

so length=lk

breath=bk

height=hk

then,

2(lb+lh+bh)=2(lk*bk+lk*hk+bk*hk)

=2(lbk²+lhk²+bhk²)

=2k²(lb+lh+bh) - [after taking k as comman]

=k²2(lb+lh+bh)

since 2(lb+lh+bh)=x

it can be written as so k²x

as x is the original surface area

so x is increased by k²