9000140502 Level: BSimplify for \(n\in \mathbb{N}\). \[ \frac{(n + 1)!} {(n - 1)!} \]\(n^{2} + n\)\((n + 1)^{2}\)\(\frac{n+1} {n-1}\)\(- 1\)
9000140503 Level: BSimplify for \(n\in \mathbb{N}\). \[ \frac{(n + 1)! + (n - 1)!} {n!} \]\(\frac{n^{2}+n+1} {n} \)\(2\)\(n^{2} - 1\)\(\frac{n^{2}-n+1} {n} \)
9000140509 Level: BFind the solution set of the equation assuming \(x\in \mathbb{N}\). \[ (x + 1)! = 6(x - 1)! \]\(\{2\}\)\(\{ - 3;\ 2\}\)\(\left \{\frac{5} {7}\right \}\)\(\left \{\frac{7} {5}\right \}\)
9000140510 Level: BFind the solution set of the equation assuming \(x\in \mathbb{N}\). \[ (x + 1)! + x! = 6x + 12 \]\(\{3\}\)\(\{2\}\)\(\{1\}\)\(\{4\}\)
9000140505 Level: BSimplify \(\frac{72!} {70!+71!}\).\(71\)\(72\)\(\frac{72} {141}\)\(\frac{72!} {141!}\)
9000138306 Level: BTwo dice are rolled. Find the probability that we get the number \(3\) at least once.\(\frac{11} {36}\doteq 0{.}3056\)\(\frac{3} {36}\doteq 0{.}0833\)\(\frac{10} {36}\doteq 0{.}2778\)\(\frac{12} {36}\doteq 0{.}3333\)
9000138307 Level: BTwo dice are rolled. What is the probability of getting \(10\) as the product of the two dice.\(\frac{2} {36}\doteq 0{.}0556\)\(\frac{10} {36}\doteq 0{.}2778\)\(\frac{1} {36}\doteq 0{.}0278\)\(\frac{5} {36}\doteq 0{.}1389\)
9000138309 Level: BTwo dices are rolled. Find the probability that we get either the same number on both dices or the sum of the numbers on both dices is \(6\).\(\frac{10} {36}\doteq 0{.}2778\)\(\frac{11} {36}\doteq 0{.}3056\)\(\frac{6} {36}\doteq 0{.}1667\)\(\frac{5} {36}\doteq 0{.}1389\)
9000140501 Level: BSimplify for \(n\in \mathbb{N}\). \[ \frac{n!} {(n - 1)!} \]\(n\)\(\frac{n} {n-1}\)\(\frac{n!} {n!-1!}\)\(- 1\)
9000140504 Level: BSimplify for \(n\in \mathbb{N}\), \(n\geq 2\). \[ \frac{n\cdot (n - 2)!} {(n - 1)\cdot n!} \]\(\frac{1} {(n-1)^{2}} \)\(\frac{(n^{2}-2n)!} {(n^{2}-n)!} \)\(\frac{n+1} {n-1}\)\(\frac{(n-2)!} {(n-1)!}\)