The sum of two digit number is 17. If the number formed by reversing the digits is less than the original number by 9,find the original number.
Answers
QUESTION.
The sum of the digit of a two digit number is 17.
if the digit is formed by reversing the digit is less than the original number by 9 . find the
original number
To find the original number,
EXPLANATION.
Let tens place digit = x
Let unit place digit be = y
original number = 10x + y
reversing number = 10y + x
according to the question,
sum of digit of two digit number = 17
x + y = 17 ....(1)
digit is formed by reversing the digit is less than the original number = 9
10x + y - 9 = 10y + x
9x - 9y = 9
x - y = 1 ....(2)
From equation (1) and (2) we get,
2x = 18
x = 9
put the value of x = 9 in equation (1) we get,
9 + y = 17
y = 8
Therefore,
Original number = 10x + y
10(9) + 8 = 98
original number = 98
The number is 98.
Let the two digits be x, and y. The given conditions are:
(x+y) = 17 ...... ( i )
(10y+x) = (10x+y+9)
So:
10y-y+x-x=10x-x+y-y+9
9y/9 = 9x/9 + 9/9
y=x+1
If the sum of the digits (x+y) equals 17, then:
x+x+1=17
2x+1 = 17–1
2x/2 = 16/2
x = 8, and y = 9 【(8+9=17)】
Verification :
(10y+x) = (10x+y+9)
10(9)+8 = 10(8)+9+9
98 = 89+9
So the number is 98.