No one wants to have it, but if one got it, he does not want to lose it. What is It?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

Replace the question mark with the correct number below.

What is the word or phrase?

John buys rice at Rs.60/kg from Britain and then sells them at Rs.5/kg in India. As a result of this, he becomes a millionaire. How come?

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

Things are just as they seem, right? Well, check again.
Can you count the number of tigers in this picture ?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?