Question

A number consists of two digits whose sum is 9 if 9 is subtracted from the number it's digit is interchanged find the number

Answer 1

Answer:

i hope this answer is helpful.

Answer 2

Answer:

The number consists of two digits. Hence we can write the number in the form 10x+y.

for ex. 43=10*4+3.

Now,

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

and if we subtract 9 from the number it's digits get interchanged. So,

10x+y-9=10y+x

which further simplifies to

9x-9y=9.....(2)

From (1) and (2)

Multiplying 9 in (1) and adding with (2) we get

9x+9y=81

9x- 9y = 9

----------------

18x =90

=> x = 5

Putting in (1)

5 + y = 9

=> y = 4.

The number is 10*5 + 4 = 54.