Can you fill the blank with the correct number?

6 30 870 756030 _____

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?

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

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

Things are just as they seem, right? Well, check again.
Can you count the number of tigers in this picture ?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.

How do you measure 45 minutes?

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

When is the top of a mountain similar to a savings account?