To simplify the fraction 3/12, you need to find the greatest common divisor (GCD) of the numerator and the denominator. The GCD of 3 and 12 is 3.
Next, divide both the numerator and the denominator by the GCD:
3 ÷ 3 = 1
12 ÷ 3 = 4
So, the simplified form of the fraction 3/12 is 1/4.