How many words can a pen with half refill write?

One day Jenifer meets the Lion and the Tiger in the Forest of Forgetfulness. She knows that the Lion lies on Mondays, Tuesdays, and Wednesdays, and tells the truth on the other days of the week. The Tiger, on the other hand, lies on Thursdays, Fridays, and Saturdays, but tells the truth on the other days of the week. Now they make the following statements to Jenifer:

Lion: Yesterday was one of my lying days.

Tiger: Yesterday was one of my lying days too.

What day is it?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

You can see three almost identical images below. Can you spot the odd one out from them?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

Name the three-letter word that can complete the below words:

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

I am white when I am dirty, and black when I am clean. What am I?

I cannot talk, but I always reply when spoken to. What am I?

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