Question

A 20m deep well with diameter 7m is dug and the earth from digging is evenly spread out to form a platform 22m×14m.Find the hieght of the platform

Answer 1

$\pi {r}^{2} h = 22 \times 14 \times h \\ \frac{22}{7} \times {7}^{2} \times 20 = 22 \times 14 \times h \\ \frac{22}{7 } \times 49 \times 20 = 22 \times 14 \times h \\ 7 \times 20 = 14 \times h \\ h = 10 \: m \: ans.$

hope it will help you

Answer 2

Answer:

2.5m

Step-by-step explanation:

Volume of well (cylinder) = volume of platform (cuboid)

Pi x r x r x h = l x b x h

22/7 x 7/2 x 7/2 x 20 = 22 x 14 x h (by simplifing)

=> 110 x 7/22 x 14 =h (by simplifing)

=> h = 2.5m