Question

If internal and external diameter of hallow hemisphere are 20cm and 28cm .find the cost of the painting at the rate of 0.14 per cm2

Answer 1

Answer:

External radius =28/2 cm=14 cm

External surface area of vessel

=2πR

2

=2×

7

22

×14×14

=1232 cm

2

....(1)

Internal radius =20/2 cm=10 cm

Internal surface area of vessel

=2πr

2

=2×

7

22

×10×10

=628.57 cm

2

.....(2)

Surface area of ring =π(R

2

−r

2

)

=

7

22

(14

2

−10

2

)

=301.714 cm

2

......(3)

Total surface area of vessel

=(1)+(2)+(3)

=1232+628.57+301.714

=2162.284 cm

2

cost of painting vessel =14p/cm

2

Total cost of painting =14×2162.284

30,271.976 paise

Now 1 Rupee =100 paise

Hence,

Total cost =Rs

100

30271.976

Totalcost=Rs\ 302.72$$

Step-by-step explanation:

HOPE THIS HELPS YOU.

STAY HAPPY, HEALTHY AND SAFE.