Question

13.The dimensions of a cuboidal tank are 1/6 ab, 12a 2 and 4b. Find the volume of the cuboidal tank. Find its volume if a =20m and b = 5m.

Answer 1

Answer:

Step-by-step explanation:

Given details are,

Ratio of dimensions of rectangular box = 2:3:4

Let length of box be ‘2x’ m

Let breadth of box be ‘3x’ m

Let height of box be ‘4x’ m

Area of sheet of paper required for covering it = total surface area of cuboid

= 2 (lb+bh+hl)

= 2 (2x×3x + 3x×4x + 4x×2x)

= 2 (6x2 + 12x2 + 8x2)

= 2 (26x2)

= 52 x2 m2

Cost for covering with sheet of paper at the rate of Rs 9.50 /m2 = 52x2 × 9.50

= Rs 494x2

Cost for covering with sheet of paper at the rate of Rs 8 /m2 = 52x2 × 8

= Rs 416x2

Given, the difference between the cost of covering it with sheet of paper at the rates of Rs 8 and Rs 9.50 per m2 is Rs 1248

494x2 – 416x2 = 12448

78x2 = 1248

x2 = 1248/78

= 16

x = √16

= 4

∴ Length of box = 2x = 2×4 = 8m

Breadth of box = 3x = 3×4 = 12m

Height of box = 4x = 4×4 = 16m