What is 9/3 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 9/3 of 15? We'll show you a straightforward method to achieve that.
How to calculate 9/3 of 15?
- Multiply the whole number by the numerator of the fraction: 15 × 9 = 135
- Divide this result by denominator of the fraction: 135/3 = 45
- Simplify by dividing both the numerator and denominator by their GCD (3):
- 135/3 = 45
- 3/3 = 1
- Which gives: 45/1
How does it work?
The principle behind finding a fraction of a number, such as 9/3 of 15, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 9/3 of 15)
- Using the cross-multiplication method, multiply both numerators by their opposite denominators:
- Which gives:
- Divide both sides by 3 to isolate x:
- Which gives the result: (or )
Thus, 9/3 of 15 is equal to 45/1 (or 45 in its decimal form).