Answer:
Original number is 47
Step-by-step explanation:
Given: The tens digit is three less than the units digit. If the digits are reversed, the sum of the reversed number and the original number is 121.
To find: the original number
Solution:
Let x denotes digit at ones place.
As the tens digit is three less than the units digit,
Digit at tens place = [tex]x-3[/tex]
Original number = [tex]10(x-3)+x=11x-30[/tex]
When digits are reversed,
Reversed number = [tex]10x+(x-3)=11x-3[/tex]
As the sum of the reversed number and the original number is 121,
[tex]11x-30+11x-3=121\\22x-33=121\\22x=154\\x=\frac{154}{22}\\=7[/tex]
So,
original number = [tex]11x-30=11(7)-30=77-30=47[/tex]
