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

What common phrase is represented by the below lines

Easy going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Medium going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Tough going:
Weak, 'I can't do it, I'm staying!'
Tough, 'Let's get going.'

Count the number of balls in picture below:

Akbar called Birbal and asked him to draw a line on the floor. He asked Birbal to make that line smaller without erasing it. Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

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

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?