Math Problem : FF.6 Gather flower petals in a schoolyard

Since the beautiful petals were scattered in the schoolyard, Taro decided to gather them together with some friends to make pressed flowers.

Although it was decided that each person gather 15 petals at a time, there were three persons who were able to gather only 14 sheets and three persons who were able to gather only 12 sheets at a time, respectively.

Then, when collecting the petals gathered and redistributing to everyone so that it might become the same number of sheets, eight sheets of petal remained.

In this case, find the number of persons who gathered petals.

Answer all the probable numbers considered.












Answer
10 persons
20 persons