Answer:
def sum_positive_numbers(n):
if(n==0 or n==1): #if n is 0 or 1 return n as its sum also will be n
return n
return n+sum_positive_numbers(n-1) #else return n and sum of all the number smaller then n
print(sum_positive_numbers(3)) # Should be 6
print(sum_positive_numbers(5)) # Should be 15
Explanation: