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

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

If an electric train is travelling south, then which way is the smoke going?

Can you divide the below-given shape into four equal and identical pieces?

Pronounced as 1 letter, And written with 3, 2 letters there are, and 2 only in me. I’m double, I’m single, I’m black blue and grey, I’m read from both ends, and the same either way. What am I?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

Outside a massage parlour, there is a board that reads
"I only massage those who do not massage themselves."

Reading the above statement, does the masseur massage himself?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

I always drive my customer away.

Who am I?

Can you solve this picture maths equation?