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

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

What do you call a fish without an eye?

Replace the question mark with the correct number in the below-given picture?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?