Crossword Help Forum
Forum Rules

I need some help with this word problem in a puzzle book.

While doing my fraction homework, I always used my "cookie" rule. A part of the "cookie" rule that I had was when I am doing my homework I can help myself to the cookies in the cookie jar, ONLY AFTER FIRST, sharing with my baby sister. The first day of fraction homework, I gave her one cookie and took one-fifth of the rest for myself. The next day, I gave her two and took one-fifth of the rest for myself. Each day, I gave her one more than previously before taking my one-fifth, until the day when her share left none for me. No cookies were added to the jar during this time. How many cookies were in the jar when I started fraction homework?

I hope to god there is a math whiz b/c this flew way over my head.

16

it would help next time if u wouldnt mind explaining how u got that number as opposed to just using any random number someone threw out there.

First number must be of the form 5x+ 1
ie 6, 11, 16, 21, 26 etc
This makes the second number in each case 4, 8, 12, 20 etc

Second number must be of the form 5y + 2
ie 7, 12, 17, 22, 27, 32 etc so only 12 fits

This makes the third number 8 and the fourth number 4 (which the sister took, leaving none left)

Hence I agree that the initial number is 16.