Set up a proportion:
[tex] \frac{660}{35} = \frac{840}{x} [/tex]
The numerator represents the words in the document, and the denominator represents the seconds it takes to print the document.
You can simplify the first fraction to make multiplication easier. Divide both the numerator and denominator by 5:
[tex] \frac{660}{35} \div \frac{5}{5} = \frac{132}{7} [/tex]
[tex] \frac{132}{7} = \frac{840}{x} [/tex]
Cross multiply both fractions:
[tex] 132x = (840 \times 7) = 5880 [/tex]
Divide both sides by 132 to get x by itself:
[tex] 5880 \div 132 = 44.54 [/tex]
[tex] \boxed{x = 44.54} [/tex]
It will take 44.54 seconds to print the 840-word document.
