What is 5/7 of 87?
Often, in mathematics or everyday life, we need to find a fraction of a given number. For instance, how would you quickly calculate 5/7 of 87? We'll show you a straightforward method to achieve that.
How to calculate 5/7 of 87?
- Multiply the whole number by the numerator of the fraction: 87 × 5 = 435
- Divide this result by denominator of the fraction: 435/7 = 62.142857142857
Since 435/7 is an improper fraction, the result could also be expressed as a mixed number: 62 1/7
How does it work?
The principle behind finding a fraction of a number, such as 5/7 of 87, is rooted in the method of cross-multiplication.
Consider the following proportion: (where x represents 5/7 of 87)
- 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:
Thus, 5/7 of 87 is equal to 435/7 (or 62.142857142857 in its decimal form).