Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

If 24H in a D => 24 hours in a day.
What does "64S on CB" stand for?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

If six children and two dogs were under an umbrella, how come none of them got wet?

What does this rebus photo means?

There was a minor accident with a doctor's son but the doctor noticed no major injury. After the treatment, the father of that doctors son is sitting with the son of the doctor without the doctor being in the room.

How can this be possible?

Solve the following series:
AZ, GT, MN, __, YB

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

0 0 0 = 6
1 1 1 = 6
2 2 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

You can use any mathematical symbols in the space provided to make all above algebraic expressions true.