MAP test practice 230

Answer all the questions below and press submit to see how many you got right.

id: 8953

How many different $n$ digit numbers are there that only use the digits 1 and 2?

  • $y=n^n$
    $y=2^n$
    $y=1\cdot 2\cdot 3 \ldots \cdot n$
    $y=\frac{n\cdot (n+1)}{2}$