Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

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

What has 13 hearts but no other organs?

What is more useful when it is broken?

A man was just doing his job when his suit was torn. Why did he die three minutes later?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Can you find out the total number of triangles in the given figure?

There are three houses in a straight row. One is red, one is blue, and one is white. The red house is left of the middle. The blue house is right of the middle. Where's the white house?

You along with your friend are standing in front of two houses. Each of those houses inhabits a family with two children.

Your friend tells you the below two facts:
1) On your left is a family that has a boy who likes accounts but the other child loves science.
2) On the right is a family with a seven-year-old boy and a newborn baby.

You ask him, "Does either of the family have a girl?"

To this, he replies, "I am not quite sure. But can you guess that? If you are right, I will give you $500."

Which family do you think is likely to have a girl?