Using Only Five 5's and any mathematical operator make sum as 37

Two friends decide to get together; so they start riding bikes towards each other. They plan to meet halfway. Each is riding at 6 MPH. They live 36 miles apart. One of them has a pet carrier pigeon and it starts flying the instant the friends start traveling. The pigeon flies back and forth at 18 MPH between the 2 friends until the friends meet.

How many miles does the pigeon travel?

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

I am the fastest animal but cannot climb the tree. What am I?

There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

What has one eye, but can’t see?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

Find the missing number in the sequence below:

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?