Question

The sum of digit of a two digit number is 7 the number obtained on reversing the order of digit is greater than original number by 9 find the number. ​

Answer 1

The sum of the digit of a two-digit number is 7. The number obtained, on reversing the order of digits is greater than the original number by 9.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To find:

The number.

Explanation:

• Let the ten's digit be M.

• Let the unit's digit be R.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

                                                      ~M + R = 7~

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When the digits are reversed, the number is 9 more than the original number.

• The original number is: 10R +M
• The reversed number is: 10M + R

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So,

    10M + R = 10R + M + 9

10M - M + R -10R = 9

9M - 9R = 9

9(M - R) = 9

M - R = 9/9

Hope this helps!          ¬ω≤