A company makes 150 bags. 23 of the bags have buttons but no zips.
35 of the bags have zips but no buttons.
49 of the bags have neither zips nor buttons.
How many bags have zips on them?

answer: 180

step-by-step explanation:

12-2=10

20-2=18

18x10=180

whole numbers.

step-by-step explanation:

we are given the average monthly rainfall (in millimeters) model r(m) for the years 1900-2009 as a function of the month number m.

as we can see m is taken for the number of months for years 1900-2009.

we know that number of months can't be a negative number or decimal number or a fraction.

so, the number of months could be only positive whole numbers.

therefore, whole numbers is more appropriate for the domain of r.