Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

What is next number in the pattern below:

131 517 192 123 ?

Can you fill the blank with the correct number?

6 30 870 756030 _____

Can you solve the below rebus?

The captain of a ship is telling you an interesting story and then poses a question. He says, “I have travelled the oceans far and wide. One time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. Can you tell me how that was possible?”

What does this mean?

CCCCCCC

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Can you count the number of triangles inside a triangle?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?