Q4 of 64 Page 80

Raju planned to stitch a cover for his two speaker boxes whose length, breadth andheight are 35 cm, 30 cm and 55 cm respectively. Find the cost of the cloth he has to buy if its costs ₹75 per sq.m.

Given:

l = 35cm, b = 30cm and h = 55cm


Total area to cover two speaker =2{ 2(lh + bh) + lb)}


= 2{2(35(55) + 30(55)) + 35(30)}


=2{ 2(1925 + 1650 )+ 1050}


=2{ 2(210) + 1050 }


= 2{7150 + 1050} = 16400 cm2 = 1.64m2


⇒ area = 1.64m2


Cost of 1m = Rs 75


Cost of 1.64 m2 = 1.64× 75


= Rs 123


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