Solution:

He will hang clock number 315 at 7:30pm. The person has been hanging the clock number which corresponds with the angle between the hour hand and the minute hand of the clock at that time.

Solution:

The answer is simple. The trains will be at same distance from Point P when they meet speaking on approximation. However, the train A will be closer to the point P by its own length if we are not taking meeting of train as perfectly overlapping.

Solution:

The correct answer to this twisted problem is four times.

You can try solving the problem with the help of two coins and if you are unable to understand, you may even disassemble some clockwork to find out.

Now to explain it, it is evident that the small one will turn 3 times against the big one. The reason is because it has 8 teeth which is 1/3 of the big one (24). But now we want the big wheel to stop and the small one to turn around the big one. In this process, the small one will make an additional turn on its way around the big one. This makes a total of four turns.

Solution:

The smart answer would have been 'I will be quite glad and will take a day off from office to celebrate the happiness with my husband.'

The nature of question is hypothetical and you can answer in the same manner too. Usually the unmarried girls will be shocked at such a question but if you are smart, you can pull it off smartly.

Solution:

Suzie took the 100 toffees from the largest tin and then she kept one of the smaller tin of toffees inside the empty tin. In this manner, when her sister checked, there were still 100 toffees in each of the tins.

Solution:

If we take the worst case, she will have to take out 12 + 1 = 13 candies.

Solution:

The first figure tells you where you have to make the cut in the paper. Now you have two pieces of paper. If you rotate the right piece to 180 degrees, you will get what is shown in the figure two. Now the hole is in the center of the paper.

Solution:

Just form an equilateral triangle, planting trees at the vertices. Now find the center of the triangle and plant the fourth three on that point. In this manner you will form a shape of tetrahedron and all the trees will have equal distance between each other.

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.

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.