1.

The sum of the digits of a 2-digit number is 11. The number obtained byinterchanging the digits exceeds the original number by 27. Find the number. ​

Answer»

GivEn:

  • The sum of the digits of a 2-digit number is 11.

  • The number obtained by interchanging the digits exceeds the original number by 27.

To find:

  • Find the number.

SoluTion:

LETS the digit of the number in one's PLACE be x and the number in ten's place be y.

Therefore, the number is xy.

As per given Question,

The sum of the digits of a 2-digit number is 11.

\implies x + y = 11

\implies y = 11 - x⠀⠀⠀⠀⠀(1)

If one's and ten's place of the number is x and y respectively.

Therefore the number is,

\implies 10y + x

Now, Put the value of x from eq(1) -

\implies 10(11 - x) + x

\implies 110 - 10x + x

\implies 110 - 9x

After interchanging,

\implies 10x + y

\implies 10x + (11 - x)

\implies 11 + 9x

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The number obtained by interchanging the digits exceeds the original number by 27.

\implies 11 + 9x = 110 - 9x + 27

\implies 11 + 9x = 137 - 9x

\implies 9x + 9x = 137 - 11

\implies 18 = 126

\implies\sf x = \cancel{ \dfrac{126}{18}}

\implies x = 7

★ Now, Put the value of x in eq(1) -

\implies y = 11 - 7

\implies y = 4

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★ Put ths value of x and y in,

\implies 10y + x

\implies 10 × 4 + 7

\implies 40 + 7

\implies 47

\therefore Hence, the REQUIRED number is 47.



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