Question

the length of a cold storage is doubled it breadth. its height is 3 metres . the area of its four walls is 180 m sq. find its volume

Answer 1

let breadth be x
so,length will be 2x
hieght=3 m

L.S.A=180 m
2(l+b)×h=180
2×(2x+x)×3=180
2×3x×3=180
18x=180
x=10m

l=20m
b=10m

vol.=l×b×h
=20×10×3
=600m×m×m

Answer 2

Answer:

Let the length , breadth and height of the cold storage be l metres, b metres and h metres respectively. Then, l = 2b (given) and h = 3 metres.

Now,

We know that,

$\\ \sf \: Area \: \: of \: \: four \: \: walls = 108 \: \: {m}^{3} \\ \\ \\ \implies \tt \: 2 \: ( \: l + b \: ) \: h = 108 \\ \\ \\ \implies \tt \: 2 \times 2b + b \times 3 = 108 \\ \\ \\ \implies \tt \: 18 \: b = 108 \\ \\ \\ \implies \tt \: b = \cancel \frac{180}{18} \\ \\ \\ \implies \tt \: b = 6 \: \: metres.$

•°• l = 2b

=> l = 12 m

$\\ \sf \: Volume = (lbh) {m}^{3} \\ \\ \\ \implies \tt \: (12 \times 6 \times 3) {m}^{ 3} \\ \\ \\ \implies \tt \blue{216 \: \: {m}^{3} }$