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
-2n + 6 is the answer to this question
Well 32 x 405 is 12,960, but it ask for 2 numbers added to make 12,960 so the answer is 810 + 12,150 which is 2 products that add up to the answer 12,960.
-6 and 6 is the answer to this
The answer is 1 and 4/5. Just divide and put the remainder as the numerator and the numerator stays the same