Question

the sum of the digits of a 2-digit number is 9 . if the digits of the number are reversed the new number is decreased by 9. find the number

Answer 1

Answer:

The required two digit number is 54

Step-by-step explanation:

Let the required two digit number be 10x+y

sum of digits is 9

Then,

x+y=9...........(1)

As per given data,

when the digits are reversed,

10y+x=(10x+y)-9

9x - 9y = 9

x -y =1........... (2)

Now, we solve (1) and (2)

x -y =1........... (2)

x+y=9...........(1)

Adding (1) & (2) we get

2x = 10

x=5

put x=5 in (2) we get

5+y=9

y = 4

The required number is 10(5)+4=50+4=54