Answer:
Using python
num_boys = int(input("Enter number of boys :"))
num_girls = int(input("Enter number of girls :"))
budget = int(input("Enter the number of dollars spent per school year :"))
try:
dollarperstudent = budget/(num_boys+num_girls)
print("Dollar spent per student : "+str(dollarperstudent))#final result
except ZeroDivisionError:
print("unavailable")