Question

Jane can type $60$ words per minute and it takes her $35$ minutes to write a letter.

John can type $50$ words per minute.

How long would it take him to write the same letter?

Answer 1

Calculate the time required by John to type the same letter

Typing speed of Jane $=60$ words per minute.
Time Jane took to write the letter $=35$ minutes.
$\therefore$Total number of words Jane wrote$=60\times 35=2100$ words.

Since John has to write the same letter, he will be typing a total of $2100$ words.
Typing speed of John $=50$ words per minute.
$\Rightarrow$Time John took to write the letter $=\frac{2100}{50}=42$ minutes.

$\therefore$John will take $42$ minutes to write the same letter.