What is 3/5 of 31?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 3/5 of 31? We'll show you a straightforward method to achieve that.

How to calculate 3/5 of 31?

  1. Multiply the whole number by the numerator of the fraction: 31 × 3 = 93
  2. Divide this result by denominator of the fraction: 93/5 = 18.6

Since 93/5 is an improper fraction, the result could also be expressed as a mixed number: 18 3/5

How does it work?

The principle behind finding a fraction of a number, such as 3/5 of 31, is rooted in the method of cross-multiplication.

Consider the following proportion: 3 5 = x 31 (where x represents 3/5 of 31)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 3 × 31 = 5 x
  2. Which gives: 93 = 5 x
  3. Divide both sides by 5 to isolate x: 93 5 = 5 x 5
  4. Which gives the result: 93 5 = x

Thus, 3/5 of 31 is equal to 93/5 (or 18.6 in its decimal form).