Whats carible usually shown on y axis

Plz which expression is equivalent to the expression below?

The multiplication property of zero states that the product of any number and 0 is 0. what must be true about either a or b to make ab=0

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?