Question

a cuboid has lateral surface area 152 cm square and total surface area 280 cm square. find the area of its top and the cost of painting the top at the rate of rupes 18 per cm square. solve it​

Answer 1

Total surface area =2*(lb+lh+bh)=2lh+2lb+2bh

Lateral surface area =2lh+2bh

Total surface area =2lh+2bh+2lb

2lh+2bh=152cm^2

So,Total surface area of cuboid =280cm^2

2lh+2bh+2lb=280cm^2

152+2lb =280cm^2

2lb=280-152

lb=128

So ,area of top of cuboid (area of upper rectangle of cuboid) =128cm^2

Cost of painting of its top=128*18

=Rs.2304