If 1+9+8=1, what is 2+8+9?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

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?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

Out of three Friends John, Jacob and Jonny one of them is a king, one is a bureaucrat, and one is a Spy.

The king always tells the truth, the bureaucrat always lies, and the Spy can either lie or tell the truth.

John says: Jonny is a bureaucrat
Jacob says: John is a king
Jonny says: I am a Spy

Tell me, Who is the king, who is the bureaucrat, and who is the Spy?

How many times in a given day, minutes and hour clock comes in a straight line ?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

In the Thar desert, 3 men found a big 24L Jar is full of water. Since there is a shortage of water so they decided to distribute the water among themselves such that they all have equal amounts of it. But they only have a 13L, a 5L and an 11-litre Jar.

How do they do it?

On my way to St. Ives I saw a man with 7 wives. Each wife had 7 sacks. Each sack had 7 cats. Each cat had 7 kittens. Kittens, cats, sacks, wives. How many were going to St. Ives?