1) Write a for loop that increases the value of all elements in a vector of 
integers called scores by the value 10.

Solution:

   for (int i = 0; i < scores.size(); i++)
   {
      scores[i] += 10;
   }


2) Write a function that passes in a vector of integers and a value and returns
   the position in the vector of the last occurence of this value or -1 if the
   value is not within the vector.

Solution:

   int last_occurrence(vector<int> v, int value)
   {
      //holds the *index* number of the most recently seen value
      int last_seen = -1;

      for (int i = 0; i < v.size(); i++)
      {
         if (v[i] == value)
         {
             //i is the position of the element equal to value
             last_seen = i;
         }
      }
      //return the position number or -1 if never found
      return last_seen;
    }