Question

A no consists of two digits whose sum is 8.if 18 is added to the no it's digit are reversed. Find the no.

Answer 1

Answer:

let unit place digit be x and tens place digit be y.

x+y=18.......(1)

x+10y+18=10x+y....(2)

solving (1)

x=18-y.....(put this value in (2))

18-y+10y+18=10(18-y)+y

36+9y=180-10y+y

36+9y=180-9y

9y+9y=180-36

18y=144

y=144/18

y=8............(put this value in 1)

x=18-8=10