Question

If 45 cookies will serve 15 students how many cookies are needed for 30 students

Answer 1

Well  15x2=30 and 45 cookies will serve 15 student and you nee to serve 30 students. So you need to multiply 45x2 because 15x2=30.
1
45
x
  2
90

so 90 cokkies are needed to serve 30 students.