Question

the sum of the digit of a two-number is 7. the number obtained by interchnging the digit exceeds the original number by 27. find the number.

Answer 1

Hey
Here's your answer !!

Let the unit's digit be x
There fore , the ten's digit be ( 7 - x ) .

Therefore the number is 10 ( 7 - x ) + x .

Number formed by interchanging the digits is
10 x + ( 7 - x ) .


So , acc. to the question ,

{ 10 x + ( 7 - x ) } - { 10 ( 7 - x ) + x } = 27
=> ( 9x + 7 ) - ( 70 -9x ) = 27
=> 9x + 7 - 70 + 9x = 27
=> 18x - 63 = 27
=> 18x = 90
=> x = 5 .

So the number is ----->
10 ( 7 - x ) + x ,
= 10 ( 7 - 5 ) + 5 ,
= 10 ×2 + 5 ,
= 25 . [ Answer ] .

Hope it helps !!