What is 10/5 of 39?

Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 10/5 of 39? We'll show you a straightforward method to achieve that.

How to calculate 10/5 of 39?

  1. Multiply the whole number by the numerator of the fraction: 39 × 10 = 390
  2. Divide this result by denominator of the fraction: 390/5 = 78
  3. Simplify by dividing both the numerator and denominator by their GCD (5):
    • 390/5 = 78
    • 5/5 = 1
  4. Which gives: 78/1

How does it work?

The principle behind finding a fraction of a number, such as 10/5 of 39, is rooted in the method of cross-multiplication.

Consider the following proportion: 10 5 = x 39 (where x represents 10/5 of 39)

  1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: 10 × 39 = 5 x
  2. Which gives: 390 = 5 x
  3. Divide both sides by 5 to isolate x: 390 5 = 5 x 5
  4. Which gives the result: 390 5 = x (or 78 1 = x )

Thus, 10/5 of 39 is equal to 78/1 (or 78 in its decimal form).