What is 3/7 of 28?
Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 3/7 of 28? We'll show you a straightforward method to achieve that.
How to calculate 3/7 of 28?
- Multiply the whole number by the numerator of the fraction: 28 × 3 = 84
- Divide this result by denominator of the fraction: 84/7 = 12
- Simplify by dividing both the numerator and denominator by their GCD (7):
- 84/7 = 12
- 7/7 = 1
- Which gives: 12/1
How does it work?
The principle behind finding a fraction of a number, such as 3/7 of 28, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 3/7 of 28)
- Using the cross-multiplication method, multiply both numerators by their opposite denominators:
- Which gives:
- Divide both sides by 7 to isolate x:
- Which gives the result: (or )
Thus, 3/7 of 28 is equal to 12/1 (or 12 in its decimal form).