2010 UNCO Math Contest II Problems/Problem 7

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Problem

$P$ and $Q$ are each $2$-digit $\underline{prime}$ numbers (like $73$ and $19$), and all four digits are different. The sum $P+Q$ is a $2$-digit number made up of two more different digits ($P+Q$ is not necessarily prime). Further, the difference $P-Q$ consists of yet two more different digits (again, $P-Q$ is not necessarily prime). The number $R$ is a two digit $\underline{prime}$ number which uses the remaining two digits. What is $R$?


Solution

$29$

See also

2010 UNCO Math Contest II (ProblemsAnswer KeyResources)
Preceded by
Problem 6
Followed by
Problem 8
1 2 3 4 5 6 7 8 9 10
All UNCO Math Contest Problems and Solutions
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