Allow us first to work out the volume of barrel of pen that is of round and hollow shape

Think about barrel,

Since 1cm = 10 mm

Base width = 5 mm = 0.5 cm

Base span, r = 0.25 cm

Stature, h = 7 cm

We realize that,

Volume of a chamber = πr2h

Volume of barrel = π (0.25)27

Volume of barrel \[=\text{ }22/7\text{ }\times \text{ }0.25\text{ }\times \text{ }0.25\text{ }\times \text{ }7\text{ }=\text{ }1.375\text{ }cm3\]

Thus, as per the inquiry,

1.375 cm3 of ink can compose 3300 words

No of words that can be composed by 1 cm3 of ink = 3300/1.375 = 2400 words

1/fifth of a liter = 0.2 L

We realize that,

1 L = 1000 cm3

0.2 L = 200 cm3

Thus, no of words that can be composed by 200 cm3 = 2400(200) = 480000 words

In this way, 1/fifth of a liter ink can compose 480000 words.