Question

a well 3.5m in radiua and 22.5m deep has to be dug . find the cost and digging the well at rupees 3.40 per cubis metre

Answer 1

$the \: volume \: of \: the \: well \: will \: be \: \\ \pi {r}^{2}h \\ now \: the \: cost \: would \: be \: \\ volume \: \times the \: cost \: given \: per \: cubic \: meter$
You may now put the values and get the answer