Nico bought a bag of jelly beans. he ate 15 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 nico bought?

We can start off by setting up an equation:

15 + (25)(3) = j

The 15 equals the number of jellybeans Nico ate @ beginning. The 25 represents the "1/3" of the remaining jellybeans in the bag AFTER Nico ate 15, thus we can multiply 25 by 3 to find out how many jellybeans were left in the bag after Nico ate some and add our product to 15.

15 + (25*3) = j
15 + 75 = j
90 = j

So, there was a total of 90 jellybeans in the bag that Nico bought.