You need to arrange three 7 and mathematical symbols to form number 1?

You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

John went to buy some expensive, foreign chocolates. He only had Rs 100 with him. When he reached the shop, he got out and know that on those chocolates, there was a 15% import duty and 5% VAT.

How much worth chocolate should he buy so that he can accommodate it in Rs 100?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

Can you decipher the below rebus?

PBLUESAISNUERSES

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

What is the next number in the series?

15 29 56 108 208 ?

How many letters are in the alphabet?

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?