How many jelly beans in the bag?

Question

Nick bought a bag of jelly beans. He ate the jelly beans and then gave one-third of the remaining jelly beans to his brother. If he gave 25 jelly beans to his brother, how many jelly beans, j, were in the bag that Nick bought?

Answer 1

The question is written incorrectly. If he "ate the" jelly beans, it would mean he finished them all. It should have said, "Ate some of the jelly beans". 

How did Mark get the 75 (which is the right answer)? Not that tough. You can set up a nice, cozy proportion. Just remember that he gave his brother 1 out of every 3 jellybeans:

 

1  =  25                         In other words, "1 out of 3 means 25 out of how many?"

3       X                          Simply cross-multiply....

 

1X = 75                         ...and since the Identity Property says you can multiply by one any time, you can also ignore it

                                     any time. That is where the 75 came from.