1.

.The sum of the two digits number is 8.the number obtained by interchanging the digits exceeds original number by 18,so what is the original number (descriptive)

Answer»

ong>Step-by-step EXPLANATION:

\bf\underline{\underline{\red{Given:-}}}

  • The sum of the TWO digits number is 8.

  • The number obtained by interchanging the digits exceeds ORIGINAL number by 18.

\bf\underline{\underline{\blue{To\:Find:-}}}

  • The original number.

\bf\underline{\underline{\green{Solution:-}}}

\sf Let\: the \: tens\: digit\: of \: the \: number \: be \: x

\sf And, \: the \: units\: digit\: of \: the \: number \: be \: y

\sf The\: original \: number = 10x + y

\sf The\: number \: obtained \: by \: interchanging \: the \: digits = 10y + x

\bf\underline{\pink{Case\: 1:-}}

The sum of the two digits number is 8.

\sf \implies x + y = 8..…..(i)

\bf\underline{\orange{Case\: 2:-}}

The number obtained by interchanging the digits exceeds original number by 18.

\sf Reversed\: number - Original\: number = 18

\sf \implies 10y + x - (10x + y) = 18

\sf \implies 10y + x - 10x - y = 18

\sf \implies 9y - 9x = 18

\sf Divide\: the \: equation \: by \: 9

\sf \implies y - x = 2......(ii)

\underline{\sf Adding \: equations\: (i) \: and \: (ii)}

\sf \implies x + y + y - x = 2 + 8

\sf \implies 2y = 10

\sf \implies y = 5

\underline{\sf Substituting\: y = 5\: in \: equation\: (i)}

\sf \implies x + y = 8

\sf \implies x + 5 = 8

\sf \implies x = 8 - 5

\sf \implies x = 3

\sf The \: original \: number = 10x + y

\sf = 10(3) + 5

\sf = 30 + 5

\sf = 35

\large\underline{\boxed{\purple{\rm \therefore The \: original \: number = 35}}}



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