A cuboid has lateral surface area 152cm² and total surface area 280cm² . Find the areo of its top and the cost of painting the top at the rate of rupees 18 per cm²
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first lateral surface area = 152
2 (l+b)×h = 152 as 2 is in multiplication so divide it by 152 you will get 76
now multiply h inside the bracket you will get lh+ bh = 76
second case
2( lb + bh + hl)= 280 now take the two below 280 and divide you will get 140
since lh + bh = 76 put this in second case
76 + lb = 140 so lb = 140 - 76 lb = 64
so area of its top is 64 cm square
ii part
multiply 68 × 14 = 1152 rupees
2 (l+b)×h = 152 as 2 is in multiplication so divide it by 152 you will get 76
now multiply h inside the bracket you will get lh+ bh = 76
second case
2( lb + bh + hl)= 280 now take the two below 280 and divide you will get 140
since lh + bh = 76 put this in second case
76 + lb = 140 so lb = 140 - 76 lb = 64
so area of its top is 64 cm square
ii part
multiply 68 × 14 = 1152 rupees
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