(Q12).A 20 m deep well with diameter 7 m. is dug and the earth got by digging is evenly spread out to form a rectangu¬lar platform of base 22 m. × 14 m. Find the height of the platform.
Answer:
Volume of earth taken out = πr
2
h
=
×
×
×
=
m
Let height of plot form = H m.
∴
×
×
=
×
×
×
H =
=
=
m
∴ The height of the plat form is
m
Clear