A rational number is a number that can be written as a ratio. That means it can be written as a fraction, in which both the numerator (the number on top) and the denominator (the number on the bottom) are whole numbers. The number 8 is a rational number because it can be written as the fraction 8/1.
33+9=42. 42-40=2. These simple calculations show that two people must have raised there hands for both because the sum of the two groups who raised hands is two more than the amount of people in the actual class