document.write( "Question 252284: Each letter in the problem to the right represents a different digit
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document.write( "All digits in NINE are odd. What is the smallest possible value of NINE?
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document.write( " FOUR
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document.write( " +FIVE
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document.write( "_________
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document.write( " NINE\r
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document.write( "a. 3135 b. 3537 c. 5153 d. 5351 e. 7173 \n" );
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Algebra.Com's Answer #184300 by Edwin McCravy(20060)![]() ![]() You can put this solution on YOUR website! \r\n" ); document.write( "Let a, b, c be the numbers \"to carry\", which\r\n" ); document.write( "can only be 0 or 1.\r\n" ); document.write( "\r\n" ); document.write( " a b c \r\n" ); document.write( " F O U R\r\n" ); document.write( "+ F I V E\r\n" ); document.write( "------------\r\n" ); document.write( " N I N E\r\n" ); document.write( "\r\n" ); document.write( "in the leftmost column a=1\r\n" ); document.write( "because if a=0, then N=2F, \r\n" ); document.write( "making N even, but N is odd.\r\n" ); document.write( "\r\n" ); document.write( "in the 2nd column from the left, \r\n" ); document.write( "\r\n" ); document.write( "b + O + I = 10 + I\r\n" ); document.write( "b + O = 10\r\n" ); document.write( "\r\n" ); document.write( "b can only be 1, for if b were 0,\r\n" ); document.write( "O would be 10, not a digit.\r\n" ); document.write( "\r\n" ); document.write( "Thus O = 10-1 = 9\r\n" ); document.write( "\r\n" ); document.write( "Now we have:\r\n" ); document.write( "\r\n" ); document.write( " 1 1 c \r\n" ); document.write( " F 9 U R\r\n" ); document.write( "+ F I V E\r\n" ); document.write( "------------\r\n" ); document.write( " N I N E\r\n" ); document.write( "\r\n" ); document.write( "From the rightmost column,\r\n" ); document.write( "\r\n" ); document.write( "R + E = E + 10c\r\n" ); document.write( "\r\n" ); document.write( "Subtracting E from both sides,\r\n" ); document.write( "\r\n" ); document.write( "R = 10c\r\n" ); document.write( "\r\n" ); document.write( "c can't be 1, for R would be 10,\r\n" ); document.write( "not a digit, so c=0. Therefore\r\n" ); document.write( "R=0, and we have:\r\n" ); document.write( "\r\n" ); document.write( " 1 1 0\r\n" ); document.write( " F 9 U 0\r\n" ); document.write( "+ F I V E\r\n" ); document.write( "------------\r\n" ); document.write( " N I N E\r\n" ); document.write( "\r\n" ); document.write( "E must be odd and less than 5, so as to \r\n" ); document.write( "carry only 0. So we have all the \"carry\"'s,\r\n" ); document.write( "and E is either 1 or 3, so we have\r\n" ); document.write( "\r\n" ); document.write( " 1 1 0 1 1 0\r\n" ); document.write( " F 9 U 0 F 9 U 0\r\n" ); document.write( "+ F I V 1 or + F I V 3 \r\n" ); document.write( "------------ ------------ \r\n" ); document.write( " N I N 1 N I N 3 \r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "The largest odd value N could be is 7, \r\n" ); document.write( "since 9 has been used. But if N were 7,\r\n" ); document.write( "then U+V would have to be 17, requiring \r\n" ); document.write( "U and V to be 9 and 8, but 9 has been \r\n" ); document.write( "used. Therefore N is either 5 or 3. \r\n" ); document.write( "But N can't be 3 because in either case\r\n" ); document.write( "above, that would make F be 1, and 1 has\r\n" ); document.write( "already been used. So N can only be 5.\r\n" ); document.write( "\r\n" ); document.write( " 1 1 0 1 1 0\r\n" ); document.write( " F 9 U 0 F 9 U 0\r\n" ); document.write( "+ F I V 1 or + F I V 3 \r\n" ); document.write( "------------ ------------ \r\n" ); document.write( " 5 I 5 1 5 I 5 3 \r\n" ); document.write( "\r\n" ); document.write( "and in both cases, F can only be 2, so\r\n" ); document.write( "now we have\r\n" ); document.write( "\r\n" ); document.write( " 1 1 0 1 1 0\r\n" ); document.write( " 2 9 U 0 2 9 U 0\r\n" ); document.write( "+ 2 I V 1 or + 2 I V 3 \r\n" ); document.write( "------------ ------------ \r\n" ); document.write( " 5 I 5 1 5 I 5 3 \r\n" ); document.write( "\r\n" ); document.write( "Now the only possibilities for U and V are \r\n" ); document.write( "8 and 7, but we can't tell which is which.\r\n" ); document.write( "They could go either way, so we have four \r\n" ); document.write( "possibilities:\r\n" ); document.write( "\r\n" ); document.write( " 1 1 0 1 1 0 1 1 0 1 1 0\r\n" ); document.write( " 2 9 7 0 2 9 8 0 2 9 7 0 2 9 8 0\r\n" ); document.write( "+ 2 I 8 1 or + 2 I 7 1 or + 2 I 8 3 or + 2 I 7 3 \r\n" ); document.write( "------------ ------------ ------------ ------------\r\n" ); document.write( " 5 I 5 1 5 I 5 1 5 I 5 3 5 I 5 3 \r\n" ); document.write( "\r\n" ); document.write( "All that's left is I, so we can easily fill that in in\r\n" ); document.write( "each case to make the addition correct, since all that's\r\n" ); document.write( "left for I in the the first two cases is 3 and 1 for \r\n" ); document.write( "the last two:\r\n" ); document.write( "\r\n" ); document.write( " 1 1 0 1 1 0 1 1 0 1 1 0\r\n" ); document.write( " 2 9 7 0 2 9 8 0 2 9 7 0 2 9 8 0\r\n" ); document.write( "+ 2 3 8 1 or + 2 3 7 1 or + 2 1 8 3 or + 2 1 7 3 \r\n" ); document.write( "------------ ------------ ------------ ------------\r\n" ); document.write( " 5 3 5 1 5 3 5 1 5 1 5 3 5 1 5 3\r\n" ); document.write( "\r\n" ); document.write( "So those are the only four possibilities, and the smallest\r\n" ); document.write( "value for NINE is 5153 in the last two cases. So the correct \r\n" ); document.write( "choice is c. 5153.\r\n" ); document.write( "\r\n" ); document.write( "Edwin\n" ); document.write( " |