Question 1058163
That cannot be, because the ratio of an older person's ages to a younger
person's age always decreases as time passes.   So it is impossible that 
the professor was 4 times the pupil's age 4 years ago and he is still 4 
times as old today.  The problem has no solution.  Maybe there was a typo,
and one of those 4's should be another number.  If so you can put the 
corrected problem in the thank-you note form below and I'll get back to 
you by email.  There is never any charge because I just do this for fun.