Replace the letters of words with a number so that the below equation holds true

BASE +
BALL
---------
GAMES
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If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

You can hear me, but you can't touch or see me.

What am I?

Solve below popular number sequence
314 159 265 358 979 323 846 ?

How do you go from 98 to 720 using just one letter?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

I shave every day, but my beard stays the same. What am I?

Why is the Hole below a Lock?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?