What number should come in place of the question mark below?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

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

Identify the 10 differences between the two given pictures.

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

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

Who always enjoys poor health?

You are on your way to visit your Friend, who lives at the end of the hill. It is his birthday, and you want to give him the cakes you have made. Between your house and his house, you have to cross 5 bridges, and as it goes in the land of make believe, there is a troll under every bridge! Each troll, quite rightly, insists that you pay a troll toll. Before you can cross their bridge, you have to give them half of the cakes you are carrying, but as they are kind trolls, they each give you back a single cake. How many cakes do you have to leave home to make sure that you arrive at a friend's house with exactly two

A man was just doing his job when his suit was torn. Why did he die three minutes later?

There are seven sisters in a house in a village where there is no electricity or any gadget.

Sister-1: Reading Novel
Sister-2: Cooking
Sister-3: Playing Chess
Sister-4: Playing Sudoku
Sister-5: Washing clothes
Sister-6: Gardening

what is Sister-7 doing ?