Notice this is a geometric progression since each number multiplied by some factor equals the next number in the sequence, in this case,

Then by applying the formula for sum to infinity of a geometric progression,
its 14n+21. 7×2n is 14n, and 3×7 is 21
Answer:
She can fill 9 boxes, and will have 4 cookies left over.
Step-by-step explanation:
9 x 12 = 108.
112 - 108 = 4