I am an odd number. Take away a letter and I become even. What number am I?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

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

which number am I?

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.

What's a single-digit number with no value?

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

Can you solve below mathematical equation?

2^1234 - 2^1233

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Replace the 'X' with any mathematical symbol to make the expression equal to 111.

18 X 12 X 2 X 3 = 111

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?