Can you fill the blank with the correct number?

6 30 870 756030 _____

Find the next number in the sequence

1, 2, 6, 21, 88, __?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

What is the next shape from answers A, B, C, and D figure?

You are playing as white and given four rooks to checkmate the black king in four moves with the following rules 1. You can place one rook every move and ensure the black king should be in check position.2. After four moves the black king should be in the checkmate position.

John and Jill are madly in love with each other. To remind Jill of his pure love, John wants to send her a ring by post but in their country where burglary is quite prominent, any package that is not locked comes under the risk of being stolen for the contents.

John and Jill possess many padlocks but neither one of them has the other key.

Can you find a way John can send the ring to Jill safely?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

I guess 76.8% of readers will like this riddle.

What's the least number of people should read this post?

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with a capacity of 4 litres, 8 litres and 10 litres and you have a large tank of water. Now you have to measure 3 litres of water precisely using those buckets. How will you do it?