People make me, save me, change me, raise me. What am I?

Name a key which is hardest to turn.

How many minutes are there in Feb 2017?

Note: The shortest answer is the correct answer.

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?

Which Travels Faster? Solve below famous picture riddle:

The current time can be represented by below textual rebus.

0
=========
B.Sc
LLB

Can you tell us the current time?

The answer I give is yes, but what I mean is no. What was the question?

There are three boxes of different sizes with three cupcakes inside each of the boxes in Christina's kitchen. At night her daughter wakes up and goes to the kitchen. She opens a box and eats all three cakes.

But in the morning Christina finds out that each box still had three cupcakes. How?

There are hundred red gems and hundred blue gems. The blue gems are priceless while the red gems equal wastage. You have two sacks one labeled Heads and the other Tails. You have to distribute the gems as you want in the two sacks. Then a coin will be flipped and you will be asked to pick up a gem randomly from the corresponding sacks.

How will you distribute the gems between the sacks so that the odds of picking a Blue gem are maximum?

Can you place six X (crosses) in below board without making three in a row in any way ?