Which alphabet letter is a question?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Prove that the below maths equation is true.

8 + 8 = 91

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

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

Can you decipher the two rows to find the hidden word?

A man dies of old age on his 25 birthday. How is this possible?

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

A worker is to perform work for you for seven straight days. In return for his work, you will pay him 1/7th of a bar of gold per day. The worker requires a daily payment of 1/7th of the bar of gold. What and where are the fewest number of cuts to the bar of gold that will allow you to pay him 1/7th each day?

Can you start the fire using two pieces of wood?