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if 18 is added to a two digit number, the digits are reversed. the sum of two digits is 8. what is the original number.
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\n" ); document.write( "If the digits are reversed, the one's place becomes the ten's place and vice versa.
\n" ); document.write( "Let t = the tens place digit
\n" ); document.write( "Let o = the ones place digit
\n" ); document.write( "If 18 is added, that means the tens place becomes t + 1 and the ones place becomes o + 8
\n" ); document.write( "However, if the sum o + 8 is greater than 9, then we need to carry a 1 to the tens place
\n" ); document.write( "The only way o + 8 < 10 is if o = 1. Since the sum of the digits is 8, that
\n" ); document.write( "would mean the tens digit would have to be 7. 71+18 does not equal 17, so we need to carry a 1.
\n" ); document.write( "So we can write this equation for the tens digit:
\n" ); document.write( "t + 2 = o
\n" ); document.write( "And since the sum of the digits is 8, we have:
\n" ); document.write( "t + o = 8
\n" ); document.write( "Substitute the value for o above into the last equation:
\n" ); document.write( "t + t + 2 = 8
\n" ); document.write( "2t = 6
\n" ); document.write( "t = 3
\n" ); document.write( "Therefore, o = 5
\n" ); document.write( "Ans: 35 \n" ); document.write( "