How many triangles can you find in this given picture?

You can find some missing letters in the picture. By placing two particular letters in the spaces, you can form a nine lettered word beginning from one of the corners and going clockwise direction to the middle. Can you find out the letters and the word?

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

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

No matter how little or how much you use me, you change me every month. What am I?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?