An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

Two trains start at the same time, one from Bangalore to Mysore and the other from Mysore to Bangalore. if they arrive at their destinations one hour and four hours respectively after passing one another, how much faster is one train running than the other?

What do you get if you add 2 to 100 four times?

What is the centre of gravity?

Find the number of squares in the below-given picture.

John asked Jack, "The time right now is 7 pm. Can you tell me what will be the time 23, 999, 995 hours later ?"

While Bella does not know the answer, do you ?

I have Rs.50 and I spend it in the way as below.

what does this picture(rebus) riddle means ?

You bought me for dinner but never eat me. What am I?

Name a key which is hardest to turn.