[ Write a function to calculate and return electricity bill. Units used are given. Price 750 units. ]
Write a function to calculate and return electricity bill. Units used are given. Price per unit is fixed and is increased after 750 units.
def calc_elect_bill(units):
if units > 0:
if units <= 750:
return 5*units
else:
return 5*(750) + 7*(units-750)
else:
return -1
