Question

A milk tin in the shape of a cuboid has dimensions 23 cm $\times$ 24 cm $\times$ 45 cm . If 1 sq.m sheet costs ₹ 10, then the total cost for making 20 such tins is _______.

• A. ₹ 136.6
• B. ₹ 106.6
• C. ₹ 126.6
• D. ₹ 116.6

Answer 1

The correct option is B ₹ 106.6

Given the dimensions of the cuboidal milk tin:
Length $\left(l\right)$ = 23 cm,
Breadth $\left(b\right)$ = 24 cm,
and Height $\left(h\right)$ = 45 cm.

Total surface area of one milk tin is
$2(lb+bh+hl)$.

Total surface area of the tin sheet required
= Total surface area of 20 milk tins

$\Rightarrow$ Area of 20 milk tins = $20\times 2(lb+bh+hl)$
$=20\times 2(23\times 24+24\times 45+45\times 23)$
$=106680c{m}^2$
$=10.66m^2$ $(\because 1m^2=10000c{m}^2)$

Cost of 1 $m^2$ tin sheet = ₹ 10.

Hence , the cost of 10.66 $m^2$ tin sheet = ₹ 10 $\times$ 10.66 = ₹ 106.6
So, total cost for making 20 such tins
= ₹ 106.6