What is 3/8 of 20?

How to calculate 3/8 of 20?

1. Multiply the whole number by the numerator of the fraction: 20 × 3 = 60
2. Divide this result by denominator of the fraction: 60/8 = 7.5
3. Simplify by dividing both the numerator and denominator by their GCD (4):
   • 60/4 = 15
   • 8/4 = 2
4. Which gives: 15/2

Since 15/2 is an improper fraction, the result could also be expressed as a mixed number: 7 1/2

How does it work?

The principle behind finding a fraction of a number, such as 3/8 of 20, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{3}{8}=\frac{x}{20}$ (where x represents 3/8 of 20)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $3\times 20=8x$
2. Which gives: $60=8x$
3. Divide both sides by 8 to isolate x: $\frac{60}{8}=\frac{8x}{8}$
4. Which gives the result: $\frac{60}{8}=x$ (or $\frac{15}{2}=x$)

Thus, 3/8 of 20 is equal to 15/2 (or 7.5 in its decimal form).