Question

In the middle of a rectangular field measuring 30m × 20m, a well of 7 m diameter and 10 m depth is dug. The earth so removed is evenly spread over the remaining part of the field. Find the height through which the level of the field is raised.

Answer 1

We have,

Diameter of well = 7 m

Radius of well = d/2 = 7/2 = 3.5m

Depth of well = 10 m

Volume of well = πr²h

= 22/7 × 3.5 × 3.5 × 10

= 385 m³

Area of embankment field = 30 × 20 – 22/7 × 7/2 × 7/2

= 600 – 38.5 = 561.5 m²

Volume of well =Area of embankment field × height of embankment

385 = 561.5 × h

h = 385/561.5

= 0.6856m

= 68.56 cm

∴ Height of embankment is 68.56 cm