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

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:

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

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:

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:

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:

The number is 37.

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

Solution:

I had 10 candies in the beginning.

Explanation:
Let us take and solve this problem in the reverse direction.

At the end, I was left with 1 candy. Let me take the extra one candy back from my younger son. Now since I gave him half of what I had, we must be having the same number of candies. I have 2, which means he also have 2. This implies that I was left with 4 candies after I gave some to the elder son.

Let me take back the extra candy from my elder son now. Now I have 5 candies. Since I gave him half of what I had, he must be having 5 candies as well. Thus, I had 10 candies in the beginning.

Solution:

When fifteen minutes have passed, the hour hand has already moved exactly one fourth of an hour. Thus the angle between the hour hand and minute hand will be of 7.5 degrees.