A = 1, otherwise the product would have 5 digits.
D = 9 because A = 1.
B = 0 or 1, otherwise the product would have 5 digits.
If B = 1, then C = 0, otherwise the product would have 5 digits.
But 1109 * 9 = 9981, which isn't right.
So B = 0. Then 9*D = 9*9 = 81, so 8 + 9*C ends with a 0 (B = 0). The only choice is C = 8
1089*9 = 9801
Please help me on this one!
ABCD
x 9
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DCBA
What is A,B,C,and D?
2 answers
This is so hard
2 answers