A family had to cross a river over a bridge at night. The father can do it in 1 minute, the mother can do it in 2 minutes, their son in 5 minutes and grandma in 10. They have a torch. The bridge can hold only 2 people.

How can they cross the bridge in 17 minutes?

Notices:
1) When there are two people on the bridge they are moving with the speed of the slowest of them.
2) It is not allowed to cross the bridge without the torch, to light from a distance, to carry each other, to throw a torch to each other.

One bacterium is put in a jar. It reproduces itself so quickly that every second each bacterium turns into two bacteria. In 60 seconds they fill the entire jar. In what time will the jar be filled with bacteria if initially two bacteria were put in the jar?

There is a room with a closed door and three light bulbs there. Outside the room there are three switches, connected to the bulbs. You may manipulate the switches as you wish. But after you open the door you can't touch them. Identify each switch with its corresponding bulb.

You have a team of workers that will do repair work in your home. They will work for 7 days. You have to pay them one small piece of gold at the end of every day. You have a big gold bar segmented into 7 equal small pieces which are connected together like a bar of chocolate. How to give them one piece of gold every day if it is permitted to break this gold bar only twice? How many segments should be in each of the three parts of the split gold bar. How to pay workers every day using these 3 parts of gold?

Check how attentive you are. Answer the questions:

1.  You are participating in a race.
     1)  You overtake the second person. What position are you in? 
     2) If you overtake the last person, then you are...?

2.  Mary's father has five daughters: 1. Nana, 2. Nene, 3. Nini, 4. Nono. What is the name of the fifth daughter?