Question

The sum of digits of a two digit number is 9. Also, nine times this number is twice the number obtained by reversing the order of digits. Find the number.

Answer 1

Answer:

Also nine times this number is twice the number obtained by reversing the order of digit. Hence, the number is 10y + x = 10 × 1 + 8 = 18.

Answer 2

Step-by-step explanation:

let

number=10y+x

ones digit =X

tens digit=y

the sum of two digits of number is 9

X+Y=9--------(1)

given in the question

9 times this number is twice the number obtained by reversing.

so,

9(10y+X)=2(10x+y)

90y+9x=20x+2y

20x-9x+2y-90y=0

11x-88y=0

dividing by 11 on both sides

x-8y=0

now putting together equation 1 and 2

X+y=9

x-8y=0

- +. -

-----------

9y=9

Y=9/9=1

putting the value of y in equation 1

x + y = 9

X+1=9

X=8

hence

the number=10y+X

=10*1+8

=18

I hope it will be helpful