Answer: b+14
Hope it helps :)
Answer:
40 14/25 years
Step-by-step explanation:
Well, this certainly is fun.
First, to find the fraction of the doctor's life which 13 years represents, subtract the fractions from 1 (and in this case l stands for lifetime):


So, multiply this equation by the reciprocal of 25/78 to isolate one of l:

years
The answer is 86.4 I believe.