What is next number in the pattern below:

131 517 192 123 ?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

What occurs twice in a week, once in a year but never in a day?

A number with an interesting property:

When I divide it by 2, the remainder is 1.
When I divide it by 3, the remainder is 2.
When I divide it by 4, the remainder is 3.
When I divide it by 5, the remainder is 4.
When I divide it by 6, the remainder is 5.
When I divide it by 7, the remainder is 6.
When I divide it by 8, the remainder is 7.
When I divide it by 9, the remainder is 8.
When I divide it by 10, the remainder is 9.

It's not a small number, but it's not really big, either.
When I looked for a smaller number with this property I couldn't find one.

Can you find it?

You need to remove two matchsticks to make the below equation true. Can you do it ?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

How many triangles are there on the puzzle below?

Joseph buys three kinds of chocolates for 100 rupees. The first one is priced at 5 rupees, second one at 3 rupees and third one at 0.5 rupees.

If he bought 100 chocolates in total, how many pieces do you think he bought each chocolate?

What is the next number in the series?

15 29 56 108 208 ?

Can you count the number of blocks in the picture below?