Answer:
66
Explanation:
There is a 2:1 ratio of boys to girls, and there are 22 more boys than girls. We can assume that 2/3 of the class are boys while 1/3 of the class is girls.
The difference between the two is 1/3. This can be found by taking away the smaller of the two from the larger, in this case it's 2/3 - 1/3. Removing the third, it's 2-1 which can be done by multiplying the two fractions by three. If we add the third back by dividing by three, we get 1/3.
This means that 22 people must be equivalent to 1/3 the total class' population. If x/3 = 22, then 22 * 3 must be x.
22 * 3 = 66, so there must be 66 students in the class.