Hello! So, when you know your fractions and percents, you know that about 33% equals 1/3. 31 is close to 33, so the best estimate for 31% of 9 is 3. When you solve it on a calculator, 9 * 31% (0.31) is 2.79, which rounds off to 3 when rounded to the nearest whole number. The answer is B: 3.
