please solve it and step-by-step
Answers
Given
The sum of digits of two-digit number = 9
If original number substracted from reversed number = 27
To find
Original number
Solution
Let the digit at unit's place be m & digit at ten's place be n.
➺ Original number = m + 10n
➺ Reversed number = n + 10m
According to 1st case :
➛ m + n = 9
➛ m = 9 - n -(Eq.1)
According to 2nd case :
➝ (n + 10m) - (m + 10n) = 27
➝ n + 10m - m - 10n = 27
➝ 9m - 9n = 27
➝ 9(m - n) = 27
➝ m - n = 27/9
➝ m - n = 3
- Putting value from (Eq.1)
➝ 9 - n - n = 3
➝ 9 - 2n = 3
➝ -2n = 3 - 9
➝ -2n = -6
➝ n = -6/-2
➝ n = 3
Now put this value in (Eq.1) :
➺ m = 9 - 3
➺ m = 6
Now finding the original number :
⟼ Original number = m + 10n
⟼ Original number = 6 + 10(3)
⟼ Original number = 6 + 30
⟼ Original number = 36
Therefore,
Original two-digit number = 36 .
QUESTION :
The sum of the digits of a two digit number is 9.
It the number is subracted from the number formed by reversing the digits, the answer is 27.
Find the number.
SOLUTION :
Let the required number be 10 X + Y
The sum of the digits of a two digit number is 9.
Hence, we can derive the following equation :
X + Y = 9....... ( 1 )
Now,
Let us find the number formed by reversing the digits.
The number formed by reversing the digits of the original number is 10 Y + X
It the number is subracted from the number formed by reversing the digits, the answer is 27.
So,
10 Y + X - ( 10 X + Y ) = 27
=> 9 Y - 9 X = 27
=> Y - X = 3...... ( 2 )
Now add Equation (1) and Equation ( 2 )
So, we get the following result :
2 Y = 12
=> Y = 6
Substituting this value in either of the equations, we can find the value of X which comes out to be 6
So the required number becomes 6 3.
ANSWER :
The number is 63.