What is the next number in the series?

15 29 56 108 208 ?

10+10 and 11+11 can give you the same answer.

Explain how?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho

The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

How many times can you subtract the number 5 from 25?

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

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

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

Count the number of triangles in the given picture.