#### Question

An open box is made of wood 3 cm thick. Its external length, breadth and height are 1.48 m, 1.16 m and 8.3 m. Find the cost of painting the inner surface of Rs 50 per sq. metre.

#### Solution

Given

Length =1.48m=148cm.

Breath =1.16m =116 cm

Height = 8.3m = 83cm

Thickness of wood = 3cm

∴ inner dimensions:

Length (148 - 2 x 3)cm = 142cm

Breadth (116 - 2 x 3) cm = 110cm

Height= (83 - 3) cm = 80cm.

Inner surface area = 2 (l + b) + lb

`=2[(142)+100)80+142xx110cm^2]`

`2(252)[80]+142xx110cm^2=55,940cm^2`

`=559.40m^2`

Hence, cost of painting inner surface area

`=5,5940xxRs.50`

`=Rs.279.70`

Is there an error in this question or solution?

Solution An Open Box is Made of Wood 3 Cm Thick. Its External Length, Breadth and Height Are 1.48 M, 1.16 M and 8.3 M. Find the Cost of Painting the Inner Surface of Rs 50 per Sq. Metre. Concept: Surface Area of a Cuboid and a Cube.