What is 1/7 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 1/7 of 15? We'll show you a straightforward method to achieve that.

How to calculate 1/7 of 15?

  1. Multiply the whole number by the numerator of the fraction: 15 × 1 = 15
  2. Divide this result by denominator of the fraction: 15/7 = 2.1428571428571

Since 15/7 is an improper fraction, the result could also be expressed as a mixed number: 2 1/7

How does it work?

The principle behind finding a fraction of a number, such as 1/7 of 15, is rooted in the method of cross-multiplication.

Consider the following proportion: 1 7 = x 15 (where x represents 1/7 of 15)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 1 × 15 = 7 x
  2. Which gives: 15 = 7 x
  3. Divide both sides by 7 to isolate x: 15 7 = 7 x 7
  4. Which gives the result: 15 7 = x

Thus, 1/7 of 15 is equal to 15/7 (or 2.1428571428571 in its decimal form).