Question

2.
Find the surface area of the cyther
A ball point pen has inner radius of 2mm and length of 90 mm. How many
mm of ink will be needed to fill it.

​

Answer 1

Step-by-step explanation:

Volume of a barrel =

7

22

×0.25×0.25×7=1.375 cm

3

Volume of ink in the bottle =

5

1

litre =

5

1000

=200 cm

3

Therefore, total number of barrels that can be filled from the given volume of ink =

1.375

200

So, required number of words =

1.375

200

×330=48000