What is the next number in the series?

15 29 56 108 208 ?

There are three boxes of different sizes with three cupcakes inside each of the boxes in Christina's kitchen. At night her daughter wakes up and goes to the kitchen. She opens a box and eats all three cakes.

But in the morning Christina finds out that each box still had three cupcakes. How?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

There is an exact a week gap between Christmas and New Year. Hence, It is obvious that the new year that comes right after Christmas comes on the same day of the week.

A Strange thing happened in the Year 1777. Christmas occurs on Wednesday and New Year on Monday. How is that possible?

Can you count the number of lines in the below picture?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

Solve the counting riddle by identifying the number of triangles in the given picture.

Next Number in the Series,

5, 16, 49, 104, ?