How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

I am a ten letters word
The first four letters have the power to rule,
Next, four-letter can be eaten.
The next three-letter represents a lady.
I can fly as well

what am I looking for?

If eleven plus two equals one, what does nine plus five equal?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

What number divided by 4 is the same as that number minus 4?

Find the next number in the sequence

5 12 24 36 ?

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?