What is 5/8 of 15?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 5/8 of 15? We'll show you a straightforward method to achieve that.

How to calculate 5/8 of 15?

  1. Multiply the whole number by the numerator of the fraction: 15 × 5 = 75
  2. Divide this result by denominator of the fraction: 75/8 = 9.375

Since 75/8 is an improper fraction, the result could also be expressed as a mixed number: 9 3/8

How does it work?

The principle behind finding a fraction of a number, such as 5/8 of 15, is rooted in the method of cross-multiplication.

Consider the following proportion: 5 8 = x 15 (where x represents 5/8 of 15)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 5 × 15 = 8 x
  2. Which gives: 75 = 8 x
  3. Divide both sides by 8 to isolate x: 75 8 = 8 x 8
  4. Which gives the result: 75 8 = x

Thus, 5/8 of 15 is equal to 75/8 (or 9.375 in its decimal form).