Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

John Went to the nearby store in a Mall to buy something for her home. Below is the conversation between the two:

John: How much for the one?
Shopkeeper: It is $2
John: How much for the Eleven?
Shopkeeper: It is $4
John: How much for the Hundred?
Shopkeeper: It is $6.

What is John buying?

The peacock is a bird that does not lay eggs. How do they get baby peacocks?

When 99 is considered higher than 100?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

John was running from 40 thieves. John has got 3 gold boxes which weigh as 4kg, 2kg, and 1kg respectively. A witty man asked John to stay with him for seven days in exchange for 1kg gold per day. John needs to stay there for seven days and also do not want to give the witty man any advance. How can John pay for his seven days stay?

Count the number of triangles in the given picture.

What has no start, end, or centre?

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?