Question

the sum of the digit of a two digit number is 9 if the digit are reversed, the number formed bear the ratio 3:8 to the original number. Find the original number. ​

Answer 1

Answer:

let ones place digit is x and tens palce digit is y

so number =10y+x

also given

x+y=9

now digit is reversed

so new number is

10x+y

also given

(10x+y)/(10y+x)=3/8

sloving this we got

80x+8y=30y+3x

or 77x-22y=0

or 7x-2y=0

also

x+y=9

multiplying this eq by 2

2x+2y=9

add the two eqn

9x=9

so x=1

y=9-1=8.

Answer 2

Answer:

27

Step-by-step explanation:

let ones place digit is x and tens palce digit is y

so number =10y+x

also given

x+y=9

now digit is reversed

so new number is

10x+y

also given

(10x+y)/(10y+x)=3/8

solving this we got

80x+8y=30y+3x

or 77x-22y=0

or 7x-2y=0

also

x+y=9

multiplying this eq by 2

2x+2y=18

add the two eqn

9x=18

x=18\9 = 2  

x=2 in x+y=9

2+y=9

y=9-2  = 7  

Ans 27.