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

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.

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

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?

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

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

In the image below, can you find the value of an angle(y)

Using Only Five 5's and any mathematical operator make sum as 37

Rectify the following equality 101 - 102 = 1 by moving just one digit.

What is next number in the pattern below:

131 517 192 123 ?