Question. Jen bought a bag of cookies and ate three-quarters of the bag that day. The next day, she ate half of the remaining cookies. She has 8 cookies left on the third day. How many cookies were in the bag to start?
Answer. 64
What step-by-step reasoning justifies that answer?
Reasoning: On the third day, Jen had half of the second day’s cookies left, so on the second day, she had 8 * 2 = 16 cookies. On the second day, she had 1 / 4 of the first day’s cookies left, so she started with 16 * 4 = 64 cookies in the bag.