Question

The surface area of a cuboid is 1372 square centimetre. If its dimensions are
in the ratio 4:2:1, then the length is:
(a) 7 cm
(b) 14 cm
(c) 21 cm
(d) 28cm

Answer 1

Answer:

Dimensions are 4x, 2x,1x

surface area = 2(4x.2x + 2x.1x + 1x.4x) = 1372

2(8x^2 + 2x^2 + 4x^2) = 1372

2×14x^2 = 1372

x^2 = 1372/28 = 49

x=7

length = 4x 4×7 = 28 Ans