Question

http://prntscr.com/8vhr9k

Answer 1

@johnweldon1993

Answer 2

I think the answer should be the third answer

Answer 3

It says the librarian need ATLEAST 20 hard cover books. Therefore h should be equal or more than 20
But we aren't given with a specific value for the paper cover books. So we will assume that is is greater than or equal to zero
The cost for p no. of books + the cost for h no. of books = the total cash given
therefore 3.5p + 8h = or< 20

Answer 4

3.5 p is derived as below.
The cost for one book = $3.5
Cost for "p" no. of books = $3.5 * p = $3.5p

8h is derived like:
The cost for one hardcover book = $8
The cost for "h" no. of hardcover books = $8h

Any doubts?

Answer 5

oh ok! thank u :]

Answer 6

No problem :)
U got it right?