Given:
In a two digit number the tens digit is 6 more than the units digit.
If the digits are interchanged, the sum of the new and the original number is 132.
To find:
The original number.
Solution:
Let the unit digit of the original number be x. So, the tens digit is (x+6) and the value of the number is:
[tex]m=(x+6)\times 10+x\times 1[/tex]
[tex]m=10x+60+x[/tex]
[tex]m=11x+60[/tex]
If we interchange the digits, then the value of new number is:
[tex]n=x\times 10+(x+6)\times 1[/tex]
[tex]n=10x+x+6[/tex]
[tex]n=11x+6[/tex]
The sum of the new and the original number is 132.
[tex]m+n=132[/tex]
[tex]11x+60+11x+6=132[/tex]
[tex]22x+66=132[/tex]
[tex]22x=132-66[/tex]
[tex]22x=66[/tex]
Divide both sides by 22.
[tex]x=\dfrac{66}{22}[/tex]
[tex]x=3[/tex]
So, the unit digit of the original number is 3 and the tens digit is:
[tex]x+6=3+6[/tex]
[tex]x+6=9[/tex]
Therefore, the original number is 39.
