2006 UNCO Math Contest II Answer Key

1) $\tfrac{13}{16}$

2) $ab+ac+bc+a+b+c$

3) $2$

4) $\{1,2,5\}$

5) $18$

6) (a) $\frac{(2^{n+1}-1)(3^{n+1}-1)}{2}$ (b) $\frac{(2^{2n+1}-1)(3^{n+1}-1)}{2}$

7) $109$

8) $\{2,4\}$

9) $a=6;b=19,c=30$ (also $2-34-47$ )

10) $13,200$

11) $\binom{7}{4}$ in general $\binom{n+3}{4}$

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