Problem 1
---------
def concatenate(L):
     i=0
     s=""
     while i < len(L):
          s = s + L[i]
          i = i+1
     return s

Problem 2
---------
def isSorted(L):
    i=1
    while i < len(L):
        if (L[i-1] <= L[i]):
            i = i+1
        else:
            return False
    return True

Problem 3
---------
def subsetOf(L1,L2):
    i=0
    while i < len(L1):
        if L1[i] in L2:
            i = i+1
        else:
            return False
    return True

Problem 4
---------
def gradeDistribution(examScores):
    distribution = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
    for score in examScores:
         if score==0:
           distribution[0] = distribution[0]+1
        else:
           distribution[(score-1)/10] = distribution[(score-1)/10]+1
            
    return distribution