Question 21
Suppose a function $M(n)$, where $n$ is a positive integer, is defined by
$$M(n)=\begin{cases}n-10,&n>100,\\M(M(n+11)),&n\le100.\end{cases}$$
How many solutions does the equation $M(n)=91$ have?
$$M(n)=\begin{cases}n-10,&n>100,\\M(M(n+11)),&n\le100.\end{cases}$$
How many solutions does the equation $M(n)=91$ have?