Question

. The lateral surface area of a cuboid
cabinet measuring 3 m x 2 m x 1 m is to
be painted. Find the cost of painting at
the rate of 80 per m
m2.​

Answer 1

LSA of cuboid= 2(lb+bh+hl)

=22m²

1m²---->rs80

22m²---->rs(80×22)= rs1760(ans)

check the calculations, but the procedure is correct

Answer 2

Given :

The lateral surface area of a cuboid cabinet measuring 3 m x 2 m x 1 m is to be painted.

To Find :

The cost of painting at the rate of 80 per m².

Solution :

Analysis :

Here the formula of lateral surface area of cuboid is used. We first have to find lateral surface area of the cabinet. Then multiplying the lateral surface area with the cost per m² we will get the total cost.

Required Formula :

Lateral surface area = 2h(l + b)

where,

• l = length
• b = breadth
• h = height

Explanation :

Lateral surface area :

We know that if we are given the length, breadth and height of a cuboid and is asked to find ita lateral surface area then our required formula is,

Lateral surface area = 2h(l + b)

where,

• l = 3 m
• b = 2 m
• h = 1 m

Using the required formula and substituting the required values,

⇒ Lateral surface area = 2h(l + b)

⇒ Lateral surface area = 2 × 1(3 + 2)

⇒ Lateral surface area = 2(3 + 2)

⇒ Lateral surface area = 2(5)

⇒ Lateral surface area = 2 × 5

⇒ Lateral surface area = 10

∴ Lateral surface area = 10 m².

The Cost :

• Cost per m² = Rs.80

We know that if we are having the lateral surface area and the cost per m² and is asked to find the total cost then our required formula is,

Cost = Area × Cost per m²

where,

• Area = 10 m²
• Cost per m² = Rs.80

Using the required formula and substituting the required values,

⇒ Cost = Area × Cost per m²

⇒ Cost = 10 × 80

⇒ Cost = Rs.800

∴ Cost = Rs.800.

Cost of painting is Rs.800.