It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

What famous saying does this rebus mean?

COME SERVED <---
COME SERVED
COME SERVED
COME SERVED
COME SERVED

In a guessing game, five friends had to guess the exact numbers of apples in a covered basket.
Friends guessed 22, 24, 29, 33, and 38, but none of the guesses was correct. The guesses were off by 1, 8, 6, 3, and 8 (in random order).

Can you determine the number of apples in a basket from this information?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

The Judge knows that Alamgir was killed by his girlfriend Jasline, but the judge is unsure whether to punish her. Why?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M