Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Can you solve the maths in the below-given picture equation?

A man dies of old age on his 25 birthday. How is this possible?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

What do you call a fish without an eye?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

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

P is the father of Q and S is the son of R. T is the brother of P and has a daughter U. If R is the sister of P, then what is the relation between U, Q and S?