What is both possible and impossible at the same time?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

1 dollar = 100 cent
= 10 cent x 10 cent
= 1/10 dollar x 1/10 dollar
= 1/100 dollar
= 1 cent

=> 1 dollar = 1 cent

solve this tricky problem?

You see me once in June, twice in November, and not at all in May. What am I?

Complete the table series riddle by finding the number that can replace "??".

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Krish is 45 years old and his mother Crishtina is 73 years old.

Can you find out how many years ago, his mother was three times his age?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?