Name: Three Dimensional Shapes
Uploaded: 2019-07-19
Duration: 4 min 42 s
Description: 3D shapes surround us everywhere. The computer, your pen, the table, and so on. In this video, learn to classify them to make sense of the world around you.

Question

Find the cost of sinking a tube well

210 m

deep, having radius

1.5 m

at the rate of

₹ 3

per

m^{3}

. How much will it cost in cementing the inner curved surface at

₹ 25

per square metre?

Accepted Answer

Given, radius of the tube well, $r = 1.5 m$

Depth of the tube well, $h = 210 m$

Volume of a cylinder $= π r^{2} h$ , where $r$ is the radius and $h$ is the height

Volume of the tube well $= \frac{22}{7} \times 1.5 m \times 1.5 m \times 210 m = 1485 m^{3}$

Cost of sinking the tube well $= ₹ 3$ per $m^{3}$

Total cost of sinking the tube well $= ₹ (3 \times 1485) = ₹ 4455$

Inner curved surface area $= 2 π r h$ , where $r$ is the radius and $h$ is the height

Inner curved surface area of the tube well $= 2 \times \frac{22}{7} \times 1.5 m \times 210 m = 1980 m^{2}$

Cost in cementing the inner curved surface of the tube well at $₹ 25$ per $m^{2} = ₹ (25 \times 1980) = ₹ 49500$

Hence, the cost of sinking the tube well is $₹ 4455$ and the cost in cementing the inner curved surface of the tube well is $₹ 49500$ .

Find the cost of sinking a tube well $210 m$ deep, having radius $1.5 m$ at the rate of $₹ 3$ per $m^{3}$ . How much will it cost in cementing the inner curved surface at $₹ 25$ per square metre?

Important Questions on Surface Area and Volume

Learn and Prepare for any exam you want !

Find the cost of sinking a tube well 210 m deep, having radius 1.5 m at the rate of ₹3 per m3. How much will it cost in cementing the inner curved surface at ₹25 per square metre?

Important Questions on Surface Area and Volume

Learn and Prepare for any exam you want !

Find the cost of sinking a tube well $210 m$ deep, having radius $1.5 m$ at the rate of $₹ 3$ per $m^{3}$ . How much will it cost in cementing the inner curved surface at $₹ 25$ per square metre?