Question

A zinc sheet is of length 3.3 m and breadth 3 m. How many pipes of length 30 cm and radius 3.5 cm can be made from this sheet?

Answer 1

length of zinc sheet = 3.3 m = 330 cm
breadth of zinc sheet = 3m = 300 cm
area of zinc sheet = area of rectangle = length × breath
= 330 × 300 = 99000 cm²
hence, area of zinc sheet = 99000cm²

length of pipe, h = 30cm
radius of base of pipe , r = 3.5 cm
so, surface area of pipe = 2πrh
= 2 × 22/7 × 3.5 × 30
= 2 × 11 × 30 = 660 cm²

$\textbf{\underline{number of pipes}}=\frac{\text{area of zinc sheet}}{\text{surface area of pipe}}$

= 99000/660 = 9900/66 = 900/6 = 150

hence, number of pipes = 150

Answer 2

Problem: A zinc sheet is of length 3.3 m and breadth 3 m. How many pipes of length 30 cm and radius 3.5 cm can be made from this sheet?

Solution:

As length and breadth are given,that means Zinc sheet is in rectangular shape.

We know that area of rectangle = length x breadth

Length =3.3 m

Breadth 3 m

Area = 3.3 x 3 = 9.9 m-square

Now length of pipe = 30 cm = 0.3 m

Radius = 3.5 cm = .035 m

Surface area of pipe = 2π rh

= 2 x 3.14 x 0.3 x .035 m-sq

= 0.06594 m-sq

Pipes made by Zinc sheet = Area of zinc sheet/Surface area of pipes

= 9.9/0.06594

= 990000/6594

= 150.13

Number of pipes formed ≈ 150 .

Hope it helps you.