Question

The sum of digits of a two digit number is 7. A number obtained after interchanging the digits is 27 more than the original number. Find the original number.​

Answer 1

let digit at ones place=x and

digit at tens place=y

So, the number will be 10y+x

x+y=7 ....(1)

reverse digit will be represented as, 10x+y

So,

(10x+y)-(10y-x)=27

9x-9y=27

x-y=3 ....(2)

Adding equation (1) and (2)

2x=10

x=5

substituting in equation (1)

y=7-5

=2

Thus, the number will be 25

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