Question

the tens digit of a number of 2 digit is greater by 7 than the unit digit .sum of the digit is 1/9 of that number ,then find the number

Answer 1

Answer:

81

Step-by-step explanation:

Let the unit and tens digit of the number be a and b respectively, so the number will be 10b+a

now, acc. to question,

b = a + 7 ----------------1

and, a + b = 1/9 (10b + a )

=> 9a + 9b = 10b + a

=> b = 8a --------------2

now from eq 1 and 2 we get,

a = 1

and b = 8

so the number is 81.