There was a strange boy who was born before his father. How can this be possible?

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

Can you find the key in the picture below?

When we see 2 but call 10?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

10+10 and 11+11 can give you the same answer.

Explain how?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?