What is 5/7 of 85?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 5/7 of 85? We'll show you a straightforward method to achieve that.

How to calculate 5/7 of 85?

  1. Multiply the whole number by the numerator of the fraction: 85 × 5 = 425
  2. Divide this result by denominator of the fraction: 425/7 = 60.714285714286

Since 425/7 is an improper fraction, the result could also be expressed as a mixed number: 60 5/7

How does it work?

The principle behind finding a fraction of a number, such as 5/7 of 85, is rooted in the method of cross-multiplication.

Consider the following proportion: 5 7 = x 85 (where x represents 5/7 of 85)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 5 × 85 = 7 x
  2. Which gives: 425 = 7 x
  3. Divide both sides by 7 to isolate x: 425 7 = 7 x 7
  4. Which gives the result: 425 7 = x

Thus, 5/7 of 85 is equal to 425/7 (or 60.714285714286 in its decimal form).