If A = {2,3,5, 7, 9, 11, 15} and B = {2,4,6, 9, 10, 14, 16} how
many elements are there in the
intersection of these two sets?

You are cycling around europe with friends. you book into a hostel and you ask the owner what the ratio of men to women is currently staying there. there are 24 men and 6 women. what is the ratio of men to women in its simplest form?

What is the value of x when x + 7 = 21?

15 and 14.7 are 1 apart, so 15 – 14.7 must be 1.