A barrel of a fountain pen, cylindrical in shape, is 7 cm long and 5mm in diameter. A full barrel of ink in the pen will be used up when writing 310 words on the average, if a bottle of ink containing one-fifth of a litre then the number of words that can be formed is

Answer

48000

Explanation

We have, `r = (5)/(20) cm = (1)/(4) cm and h = 7 cm`
Volume of the full barrel `= pir^(2) h = ((22)/(7) xx (1)/(16) xx 7) cm^(3) = (11)/(8) cm^(3)`
Given, volume of ink `= ((1)/(5) xx 1000) cm^(3) = 200 cm^(3)`
`(11)/(8) cm^(3)` is sufficient to write 330 words.
`200 cm^(3)` will be sufficient to write `(330 xx (8)/(11) xx 200) = 48000` words.