Let Jason\textquotesingle s age five years ago be 1 unit. Then Jennifer\textquotesingle s age was 5 units.  Now, Jason\textquotesingle s age is 1 unit + 5 and Jennifer\textquotesingle s age is 5 units + 5. We also know that Jennifer\textquotesingle s age is four times Jason\textquotesingle s age or 4 x (1 unit + 5) = 4 units + 20.  Then:~  5 units + 5 = 4 units + 20  5 units - 4 units = 20 - 5  1 unit = 15  Jennifer is 5 units + 5 = 5x15 + 5 = 80 years old now. 
Five years ago, Jennifer\textquotesingle s age was five times Jason\textquotesingle s age. Now, Jennifer\textquotesingle s age is four times Jason\textquotesingle s age. How old is Jennifer now? 
[1] $$20$$ 
[2] $$60$$ 
[3] $$80$$ 
[4] $$100$$ 
[5] None of the above 