Mark bought a notebook for $1.45 and some pencils the pencils cost $0.42 each the total cost of the notebook and pencils was $6.91 how many pencils did mark buy

1.45 + .42p = 6.91

subtract 1.45 from each side

.42p = 5.46

divide by .42

p =13

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.