A number consists of two digits whose sum is 7. If 45is added to the number, the digits are reversed.Find the number

Asked by daskousik2004 | 21st Aug, 2020, 10:35: PM

Expert Answer:

 
 
Let the two digit number be 10x+y.
 
A number consists of two digits whose sum is 7.
 
x + y = 7 → y = 7 - x
 
The two digit number 10x+y = 10x + 7 - x = 9x + 7

According to the condition, we get
 
9x + 7 + 45 = 10(7-x) + x
→ 9x + 52 = 70 - 9x
→ 18x = 18 → x = 1
y = 7 - 1 = 6
 
So, the required two digit number = 9(1) + 7 = 16



 

Answered by Yasmeen Khan | 22nd Aug, 2020, 11:05: PM