What is 3/9 of 39?

How to calculate 3/9 of 39?

1. Multiply the whole number by the numerator of the fraction: 39 × 3 = 117
2. Divide this result by denominator of the fraction: 117/9 = 13
3. Simplify by dividing both the numerator and denominator by their GCD (9):
   • 117/9 = 13
   • 9/9 = 1
4. Which gives: 13/1

How does it work?

The principle behind finding a fraction of a number, such as 3/9 of 39, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{3}{9}=\frac{x}{39}$ (where x represents 3/9 of 39)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $3\times 39=9x$
2. Which gives: $117=9x$
3. Divide both sides by 9 to isolate x: $\frac{117}{9}=\frac{9x}{9}$
4. Which gives the result: $\frac{117}{9}=x$ (or $\frac{13}{1}=x$)

Thus, 3/9 of 39 is equal to 13/1 (or 13 in its decimal form).