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

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

Which is faster, Heat or Cold ? Explain.

There are 3 apples in the basket and you take away 2. How many apples do you have now?

What country can make you shiver?

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

A mules travels the same distance daily.
I noticed that two of his legs travels 10km and the remaining two travels 12km.
Obviously two mules legs cannot be a 2km ahead of the other 2.

The mules is perfectly normal. So how come this be true ?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

Can you count the number of quadrilaterals in the picture below?