Question

7. Find the cost of whitewashing 20 cylindrical pillars of height 15m and radius 0.7m at Rs 5/m².


8. Find the volume of metal used in making a l m pipe of external radius 3 cm and width 0.5 cm.​

Answer 1

Answer:

7- rs 2310 cost for white wash

Answer 2

Answer:

Step-by-step explanation:

rs 2310 cost for white wash

Given length or height of pillar =3.5m

Radius of each pillar =36cm

CSA of pillar =2πrh=2π×0.36×3.5

CSA=7.91m  2

 

Now total area to be painted =7.91×20

Total Area =158.20m  2

 

Cost of painting =158.20×3=474.60.