Recursion Tracing Exercise:exec Return

Khan.randRange(2, 10) n*(n+1)/2

Consider the following function: public int exec(int n) { if (n == 0) return 0; else return n + exec(n - 1); } What value does exec(n) return?
(Either write a number, or write "infinite recursion".)

ANS

By tracing this recursive function, you should find that the result is the sum of the integers from 1 to n.