## Realated Questions

From a cask of milk containing 30 litres, 6 litres are drawn out and the cask is filled up with water. If the same process is repeated a second, then a third time, what will be the number of litres of milk left in the cask?

How many keystrokes are needed to type numbers from 1 to 1000 on a standard keyboard?

How many three digit numbers can be formed using the digits 1,2,3,4,5,6,7 and 8without repeating the digits and such that the tens digit is greater than the hundreds digit and less than the units digit?