Given the following declarations, determine which calls are legal and which are illegal. For those that are illegal, explain why

Given the following declarations, determine which calls are legal and which are illegal. For those that are illegal, explain why.

double calc(double);
int count(const string &, char);
int sum(vector<int>::iterator, vector<int>::iterator,
int);
vector<int> vec(10);

(a) calc(23.4, 55.1);

(b) count("abcda", 'a');

(c) calc(66);

(d) sum(vec.begin(), vec.end(), 3.8);