Question

Tania took selfies with her 8 cousins. Each cousins is in 2 or 3 picture. There are exactly 5 cousins on each picture. How many selfies did Tania take?

Answer 1

4

Explanation:

How many selfies did Tania take? (my first answer would be too many, but that's probably not the answer you're looking for :-) )

We know that each cousin appear 2 or 3 times overall.

If she would have taken each cousin exactly 2 times, that would be 16 cousins/photos

If she would have taken each cousin exactly 3 times, that would be 24 cousins/photos

We know there's exactly 5 cousins per photo...

so we have to find a multiple of 5 cousins/photos that is between 16 and 24.

The only possibility is 20 cousins/photos. 20 / 5 = 4 photos.