Let us first calculate the volume of barrel of pen that is of cylindrical shape
Consider barrel,
Since 1cm = 10 mm
Base diameter = 5 mm = 0.5 cm
Base radius, r = 0.25 cm
Height, h = 7 cm
We know that,
Volume of a cylinder = πr2h
Volume of barrel = π (0.25)27
Volume of barrel = 22/7 × 0.25 × 0.25 × 7 = 1.375 cm3
Hence, according to the question,
1.375 cm3 of ink can write 3300 words
No of words that can be written by 1 cm3 of ink = 3300/1.375 = 2400 words
1/5th of a liter = 0.2 L
We know that,
1 L = 1000 cm3
0.2 L = 200 cm3
So, no of words that can be written by 200 cm3 = 2400(200) = 480000 words
Therefore, 1/5th of a liter ink can write 480000 words.