1.

The sum of the digits of a two digit number is 9 . Also nine this number is twice the number obtained by reversing the order of the digits. Find the number​

Answer»

HERE'S YOUR ANSWER

LET THE DIGIT AT UNITS PLACE BE Y AND

THE DIGIT AT TENS PLACE BE X

No.= 10X+Y

No. after reversing the digits = 10Y+X

ACCORDING TO THE QUESTION

X+Y=9 (EQ.1)

X=9-Y (EQ.3)

9(10X+Y)=2(10Y+X)

90X+9Y=20Y+2X

88X-11Y=0 (EQ.2)

SUBSTITUTING X IN (EQ.2)

88(9-Y)-11Y=0

792-88Y=11Y

792=99Y

Y=792/99=8

SUBSTITUTING Y IN (EQ.3)

X=9-Y

X=9-8

X=1

NOW NO.= 10X+Y=10(1)+8=18

HOPE IT HELPS


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