$441.01 - 232.99 + 1649.99 = ? + 1225.92$

In a two-digit number,the digit in the unit's place is $1$ more than twice the digit in the ten's place. If the digits in the unit's place and the ten's place are interchanged,the difference between the new number and the original number is $1$ less than the original number. What is the original number?

What is the value of $68 \%$ of two-fifths of $550\, ?$

When a certain number is multiplied by $7$,the product consists entirely of fives; find the least value of such a number.

The digits indicated by $^*$ in $3422213^{**}$ so that this number is divisible by $99$ are

The least number which when divided by $6, 9, 12, 15, 18$ leaves the same remainder $2$ in each case is