Can you replace the question mark with the correct number in the below table sequence?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Decode this picture on T-Shirt and tell what it says ?

Find the next number in the sequence

5 12 24 36 ?

How many triangles are there in the picture below?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

Most people think of me as money. But when they find me in the water, they won’t get any money out of me. What am I?

What's the next in the series?

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

Why is the Hole below a Lock?