If all Goats are Sheep and all Sheep are Deers, are all Deers Goats ?

Two fathers and two sons decided to go to a shop and buy some sweets upon reaching. Each of them bought 1 kg of sweet. All of them returned home after some time and found out that they had 3kg of sweets with them.

They did not eat the sweets in the way, nor threw or lose anything. Then, how can this be possible?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

I am the fastest animal but cannot climb the tree. What am I?

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.

I look at you, you look at me I raise my right, you raise your left. What am I?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

Replace the question mark with the number below given a simple math problem.

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

Which Burger Is Different in below image?