Alright so one dozen cookies is 12 cookies. So 40 dozen cookies is 480 cookies (40x12). If there’s 157 students then u divide 480 by 157 which gets u 3.06 cookies per person
6/8a+4,6-2/4a. I think that this is the answer.
N ≤ 2, if n plus 7 is less than or equal to 9 (n+7 ≤ 9) then carry the 7 over to create n ≤ 9-7 giving the answer n ≤ 2 (n less than or equal to 2)

bearing in mind, "t" is in years, 6months is just 1/2 year
solve for "r", you'd get a decimal amount, multiply times 100, to get the percentage form