Solution:

400

Explanation:
Begins with 15
2*15-1 => 29
2*29-2 => 56
2*56-4 => 108
2*108-8 => 208
2*208-16 => 400

Solution:

At first, there were 2 apples on the tree. After the wind blew, one apple fell on the ground. So there where no apples on the tree and there were no apples on the ground.
*apples => more than one apple

Another solution(non tricky one)
The wind blew so hard that the apples fell of the tree and blew along the ground.

Solution:

1113213211


Explanation
1
one one => 11
two one => 21
one two , one one = > 1211
one one , one two , two one => 111221
three one , two two one one => 312211
one three, one one , two two, two one =>13112221

=>one one , one three, two one, three two, one one

Solution:

Put one red marble in one box and all other marbles in the 2nd box.

Probability :
50 + 24/49

Solution:

Belgium, Chile, Fiji, Egypt

Solution:

Unquestionably

Solution:

I an oxford dictionary where "arcade" comes before "because", because "because" begins with "B".

Solution:

One Minute building

building 62 => Sixty second building => One minute building

Solution:

Forty

Solution:

52

sum of consecutive prime numbers
(2+3 , 5+7 , 11+13 , 17+19 , 23+29)