What has no start, end, or centre?

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 have Rs.50 and I spend it in the way as below.

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

A Child was born in Lahore, Pakistan. Still, the child is not a Pakistani citizen. why?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

You see me once in June, twice in November, and not at all in May. What am I?