Replace the question mark with the number below given a simple math problem.

Find the next number in the series below.

6 18 270 72090 ?

It is always ahead of me yet I can never see it. What is it?

Can you count the number of triangles inside a triangle?

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?

You can hear me, but you can't touch or see me.

What am I?

John, a 5-year-old boy, was really fond of the chocolates. He asked his Mother to give him some money to buy his favourite chocolates. His Mother gave him $45. He went to the shopkeeper and asked, "How much is one chocolate for?". The shopkeeper said $3 for one chocolate. Also, if you give me the wrappers of three chocolates, I will give you one for the exchange.
In total, how much chocolate could John eat?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

Prove that the below maths equation is true.

8 + 8 = 91

What is greater than gold but cannot be bought. it can never be sold and can earn if its sought. though it can be broken, it can still be fixed. for by birth it can't start nor by death it is ended.what am i?