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

A river should be crossed by a father, a mother and their two sons and two daughters.
There are some rules that should be followed while crossing the river. There can be only two people in the raft while crossing. The daughters cannot be with their father unless there is the presence of the mother. The sons cannot be with their mothers unless the father is present. Unless the guard is on the board, the criminals cannot be with any of the family members. Only the adults like the father, the guard, and the mother knows to use the raft.

How will they cross the river?

Can you make a fire with just a single stick?

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

No matter how little or how much you use me, you change me every month. What am I?

There is a place where if I stand up straight, I will still be considered sideways.

There is a hypothetical state between the USA and Mexico border 'Tango'.
Here 70 percent of the population have defective eyesight, 75 percent are hard of hearing, 80 percent have Nose trouble and 85 percent suffer from allergies, what percentage (at a minimum) suffer from all four ailments?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

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?

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