Decode this picture on T-Shirt and tell what it says ?

What can you see in the middle of March and April that you can never see in any other month?

John and his team plan to rob a safe. They got just one chance to break the code else the local police will be informed. Below are clues:
A) Exactly one number is perfectly placed: 9 8 1
B) Everything is incorrect: 9 2 4
C) Two numbers are part of the code of the safe but are wrongly placed: 0 9 3
D) One number is part of the code of the safe but is wrongly placed: 1 4 7
E) One number is part of the code of the safe but is wrongly placed: 7 8 3

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?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

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.

There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb?

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

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?