Question

find the cost of plastering the curved surface of well 9 metres Deep and 21 metres in diameter at the rate of 30 per metre square​

Answer 1

STEP BY STEP EXPLANATION:-

GIVEN:-

height of well = 9metres

diameter = 21 metres

radius = 21/2 metres

cost of plastering per metre square = ₹30 per metre square

TO FIND:-

drink cost of plastering per metre square

SOLUTION:-

CSA OF CYLINDRICAL WELL = 2πrh

= 2 × 22/7 × 21/2metre × 9metre

= 2 × 11 × 3 × 9 metre square

= 22 × 27 metre square

= 594 metre square

COST OF 1 METRE SQUARE = ₹ 30

COST OF 594 METRE SQUARE = ₹ 30 × 594

= ₹ 17,820

_____________THE END _________________