Question

A box made of sheet metal costs rupees 2820 at the rate of rupees 30 per square metre if the box is 5 M long 4 m wide find its height

Answer 1

Length = 5 m

Width = 4 m

Cost = Rs 2820

Rate = Rs 30 / m^2

Total Surface Area = Cost / Rate

=> 2( LB + BH + HL) = 2820/30

=> 2( 5*4 + 4H + 5H) = 94

=> 20 + 9H = 47

=> 9H = 27

=> H = 3

Height = 3 m

Answer 2

huhiii!!!

here's ur answer...

given the cost of making a box ₹30 per m² is ₹2820.

therefore area of the metal sheet which is used to make the box = 2820/30

= 94m²

given length of the box is 5m and breadth is 4m.

TSA of the box = 94m²

therefore 2(lb+bh+lh) = 94m²

=> 2[(5×4)+(4×h)+(5×h)] = 94m²

=> 2(20+4h+5h) = 94m²

=> 40+18h = 94m²

=> 18h = 94-40

=> 18h = 54

=> h = 54/18

=> h = 3m

VERIFICATION:-

TSA of the box = 2(lb+bh+lh)

= 2[(5×4)+(4×3)+(5×3)]

= 2(20+12+15)

= 2×47

= 94m²

hence verified

thus the height of the box is 3m.

hope this helps..!