Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

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?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

How many triangles are there on the puzzle below?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

A newspaper is supposed to have 60 pages.Pages 14 and 21 are missing from the newspaper.

Can you tell me , Which other pages won't be there as well ?

Can you find out the remainder when 3^300 is divided by 5?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?