Solution:

The number is 37.

The missing guess can be either 24 or 50 and the missing difference is 8.

Solution:

You are second in position. When you overtook the second positioned person, you actually took his place and thus you are positioned second now.

Solution:

1st Bag = One Coin
2nd Bag = Two Coins
3rd Bag = Four Coins
4th Bag = Eight Coins
5th Bag = Sixteen Coins
6th Bag = Thirty Two Coins
7th Bag = Sixty Four Coins
8th Bag = One Hundred and Twenty Eight Coins
9th Bag = Two Hundred and Fifty Six Coins
10th Bag = Remaining Coins.

Now imagine any amount in your mind and you will find out that you can give any amount by just using the pouches (without opening them)

Solution:

Since the answers were different every time, the first one cannot be Sarah as that would make the first one a liar. For similar reason, even the second one can’t be Sarah. Therefore, the third one must be Sarah. If she is Sarah, the middle one must be Sue which leaves the left one to be Sally.

Solution:

I have just two tee shirts neither of which are green, blue or orange in color.

Solution:

Since you can't identify which tablets are meant for which purpose, what you can do is take half of each tablet. In this manner, you will be able to get 1 of each tablet no matter what.

Solution:

The image that we have attached here is self-explanatory. You just have to move four matches and you can obtain this figure.

Solution:

There is only one way to do it. The old man must ask one of his son to divide the land in two parts and then ask the other one to pick up any land he want from the two. In this way, the first son will try to be fair and the second one won't mind as he will get to choose one first.

Solution:

The only possible way to do it is to form an equilateral triangle pyramid and then place the balls at the corners of the figure. Yes, you will have to use 3 dimensional figure.

Solution:

No one can take out any money from the taxi meter because it simply does not contain any money. It just has a timer installed that is used to decide the fare as per the distance covered.