How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Can you spot the man between the coffee bean in the picture below ?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Spot the cat in the picture below

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

Find the value of "?" in the ball picture Riddle below:

A bridge is about to collapse. There are four people P, Q, R and S on one of the sides. Before the bridge collapses, they want to cross it. Now since the bridge is too weak, it can only stand the weight of two people at a time. Also, it is night time and nothing is visible. They have just one torch with them.

Now P takes one minute to cross the bridge, Q takes two minutes to cross, R takes five minutes to cross and S takes ten minutes to cross.

The bridge will collapse in seventeen minutes. How will they be able to cross the bridge before it collapses?

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

Find the last number in the series below:

voN luJ yaM raM ---