Skip to main content
OlympiadHQ

Browse · harp

Print

imc

number theory intermediate

Problem

In the addition shown below , , , and are distinct digits. How many different values are possible for ? \begin{array}[t]{r} ABBCB \\ + \ BCADA \\ \hline DBDDD \end{array}
(A)
(B)
(C)
(D)
Solution
Note from the addition of the last digits that . From the addition of the frontmost digits, cannot have a carry, since the answer is still a five-digit number. Also cant have a carry since then for the second column, cant equal . Therefore . Using the second or fourth column, this then implies that , so that and . Note that all of the remaining equalities are now satisfied: and . Since the digits must be distinct, the smallest possible value of is , and the largest possible value is . Thus we have that , so the number of possible values is
Final answer
C