using four eights (8) and a one (1) and one mathematical symbol , create the number 100

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

There was a strange boy who was born before his father. How can this be possible?

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

What has many teeth, but cannot bite?

Can you count the number of triangles in the given picture?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

If a wheel has 54 spokes, how many spaces are there between the spokes?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.