Can you identify the hidden rebus in the image below?

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

I am quite hot but become too cold if you remove the first two letters. What am I?

Spot 5 differences in two Christmas tree below:

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

Once upon a time, there was a castle on a square island. The entire island was surrounded by a 14m wide trench. The Romans had wanted to invade the castle and had brought a few wooden planks along with them to facilitate themselves in crossing the moat. The planks were however found to be only 13m long.

The Romans still managed to cross the trench. How did they do it?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

Find the next number in the sequence

5 12 24 36 ?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?