Cristina was born in 1888. She just had her 30th birthday today how did that happen?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

What has 88 keys?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

A man dies of old age on his 25 birthday. How is this possible?

How many triangles can you count in the figure given?

If 21x = 79x, what is the value of x?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

The following four words might seem abrupt to you. But you can make them meaningful by just adding vowels.
RDSH
GGPLNT
TMT
NN

Hint: All of them are vegetables.

Today is John's birthday.
A year ago, John had five candles and he lit all the candles except the one at the last.
Now he is going to light all the candles.

How old is John Today?

(He is not five today.....)