Can you find out who is the kidnapper in below Picture and why, Explain ?

I went to the bookshop and spent one-half of the money that was in my purse.

When I came out, I found that I had as many cents as I had dollars and half as many dollars as I had cents when I went in. Find the money in my purse when I entered the store.

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

I can write cow in 13 letters.

Can You?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

There is a river to cross using a river raft and there are eight people (father, mother, policeman, thief, 2 daughters and 2 sons). No one knows to operate the raft except the adults and also excluding the thief. Only two people can go in the raft at a time. The raft should keep coming back and forth in order to pick and drop the people.
Rules to be followed:
Father: the father cannot stay in the raft or outside the raft without the presence of the mother.
Mother: the mother cannot stay in the raft or outside the rat without the presence of the father.
Thief: the thief is not allowed to stay with any of the family members unless there is a policeman.
Policeman: the policeman can travel with anyone.
2 sons and 2 daughters: they are not allowed to travel in the raft without the presence of an adult. They cannot either travel in the presence of only thieves without the policeman. The sons cannot be with their mothers without their father's supervision. The daughters are not allowed to be there with their fathers without the supervision of their mothers. But the daughters and the sons can be left unsupervised (as long as the other rules are applied).
What is the sequence that the people should follow in order to cross the river through the raft keeping in mind all the rules?
The rules are applicable not only in the raft but also outside the raft.

When can we add 2 to 11 and get 1 as the correct answer?

How many triangles are there in the picture below?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?