Can you find out which number multiplied by itself will give the output as 12345678987654321?

Find the number of squares in the below picture

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

A father's child, a mother's child, yet no one's son.

Who am I?

What Deficiency does the below rebus represent?

VIT_MIN

Only one color, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

Can you solve below mathematical equation?

2^1234 - 2^1233

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

Can you count the number of blocks in the picture below?