What is 1/9 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 1/9 of 15? We'll show you a straightforward method to achieve that.
How to calculate 1/9 of 15?
- Multiply the whole number by the numerator of the fraction: 15 × 1 = 15
- Divide this result by denominator of the fraction: 15/9 = 1.6666666666667
- Simplify by dividing both the numerator and denominator by their GCD (3):
- 15/3 = 5
- 9/3 = 3
- Which gives: 5/3
Since 5/3 is an improper fraction, the result could also be expressed as a mixed number: 1 2/3
How does it work?
The principle behind finding a fraction of a number, such as 1/9 of 15, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 1/9 of 15)
- Using the cross-multiplication method, multiply both numerators by their opposite denominators:
- Which gives:
- Divide both sides by 9 to isolate x:
- Which gives the result: (or )
Thus, 1/9 of 15 is equal to 5/3 (or 1.6666666666667 in its decimal form).