What is common among 11, 69, and 88?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

No matter how little or how much you use me, you change me every month. What am I?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Count the number of triangles in the given picture.

There are five men, let's say Tarun Harish Lavesh, Manoj, and Manish. All of them have a dot mark on their forehead. They can't see the dots on their forehead but can see the ones on others. The owner of WHITE Dot is an honest person and will never lie, while the owner of BLACK Dot always tells the lie.

This is the statement from Tarun Harish Lavesh and Manish:
Tarun: 'I see 3 whites and 1 black'
Harish: 'I see 4 black'
Lavesh: 'I see 3 black and 1 white'
Manish: 'I see 4 white'

What colour is the dot on each of Tarun Harish Lavesh, Manoj, and Manish's forehead?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

A man died, leaving $10,000,000 for his widow, 5 sons and 4 daughters. Each daughter received an equal amount, each son received twice as much as a daughter, and the widow received three times as much as a son.

How much did the widow receive?