Possible if they dont have to pay on the same months
Whenever you have a root of sqrt #, you must have the matching - (or positive).
This is because when you take a square root you get two solutions a positive and a negative.
The answer is LETTER A
She will need to buy 3 more cookies because 2 dozens is 24. And 16 cookies plus 5 is 21 cookies plus 3 is a dozen cookies which is 24
24=16 chocolate cookies+5 peanut cookies+3 random cookies