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

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

In a particular village, only two barbershops exist.

The first shop has a handsome barber with a neat haircut who is handsomely dressed in clean clothes and is extremely humble with his body language. The place is clean and looks hygienic.

In the second shop, you can find a barber with shabby clothing. His hairs are weirdly cut and his clothes still have the stains from last night's dinner. The place is not clean as well and reeks a bit.

You visit the village for the first time and decide to get your haircut. Which barbershop will you like to go for that and why?

You are offered an opportunity to win a fortune. There are 100 precious black stones and 100 unworthy white stones. There are two different sacks labelled as "Heads" and "Tails". You can distribute the stones as you wish. Then a coin will be flipped. Then you will have to choose a stone from the corresponding sack. If you pick up a black stone, all the fortune of black stones is yours but if you pick up white, you get nothing.

How will you distribute the stones so that you can maximize your chances of winning?

Find the missing value of "?" in the letter sequence below.

CAD
EBG
KBM
OCR
DDH
NL?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

Can you find out a way through which you can make five squares out of the given figure by moving just six match sticks?

People are waiting in line to board a 100-seat aeroplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise, they will choose an open seat at random to sit in. The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?