Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

What is the last thing you take off before bed?

In the image given, you can find several triangles. Can you count them all?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

During which month do people sleep the least?

You are stuck on an island where you have nothing. You find four pieces of paper somewhere on the island. What will be your strategy to escape from the island safely?

PS: No other resource is available to you on the island, neither can you build anything.

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

What is the word or phrase?

What building has the most stories?