Question

the length of a rectangular wooden board is thrice its width . if the width of the board is 20 cm find the cost of framing it at the rate for 5 rupees for 20 cm

Answer 1

Width = 20cm
Length = 3× width
Length = 3×20=60 cm

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Perimeter of board = 2(length + breadth)

Perimeter of board = 2(20+60)

Perimeter of board = 2(80)=160 cm

Cost of framing = 160/20 ×5

Cost of framing = 8×5=₹40


:-)

Answer 2

Given,

Breadth = 20 cm

Length = 3 x Breadth = 3 x 20 cm = 60 cm.

Perimeter of Rectangle = 2 ( Length + Breadth )

                                      = 2 ( 20 cm + 60 cm )

                                     = 2 ( 80 cm )

                                      = 160 cm.

The framing is done the edges of any thing and perimeter is sum of all edges.

∵ The cost of framing 20 cm is Rs. 5

∴ Cost of framing 1 cm will be Rs. 5 / 20 = Rs. 1/4.

∴ Cost of framing 160 cm will be Rs. ( 1 x 160 ) / 4 = Rs. 40

Your answer is Rs.40.