sum of digits of two digit number is 12 if the number obtained by reversing is 18 more than the original number , and the find the original number ¿?
Answers
Answer :
Explanation :
✦ Given :–
- Sum of a two digit number is 12.
- Number obtained by reversing the digits will be 18 more than the Original Number.
✦ To Find :–
- The Original Number.
✦ Solution :–
Let the First digit of the Original Number be x and the Second digit be y .
→ According to the First Condition :-
x + y = 12 ------------(1)
→ According to the Second Condition :-
=> 10y + x = 18 + ( 10x + y )
=> 10y + x = 10x + y + 18
=> 10y - y + x - 10x = 18
=> 9y - 9x = 18
=> 9 ( y - x ) = 18
=> y - x = ( 18 ÷ 9 )
=> - ( x - y ) = 2
=> x - y = ( -2 )
=> x = y - 2 -------------(2)
Putting the Value of 'x' from Equation(2) in Equation(1) :
=> ( y - 2 ) + y = 12
=> y + y - 2 = 12
=> 2y = 12 + 2
=> 2y = 14
=> y = 14 ÷ 2
=> y = 7
Now , we have to find the both digits of the number.
➨ First Digit ( x ) = y - 2 = 7 - 2 = 5
➨ Second Digit ( y ) = 7
We have First Digit as 5 and the Second as 7.
∴ The number is 10x + y = 10(5) + 7 = 50 + 7 = 57
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☆ Additional Information :-
We write a two-digit number in the form of 10x + y where x is first digit and y is the second digit.
Let's take an example :
Let say we take a number 42
We will write it in the form of 10x + y.
10(4) + 2 where first digit is 4 and the second digit is 2.