Question 29113
Points for the midterm exam is 2/3 X 64 = 42.67.
Therefore to get a 70 composit score he need to score an additional 27 1/3 points on his final test. But this score only counts for 1/3 of his grade.

For the 70 average he needs an additional 27 1/3 points. But he only gets 1/3 credit therefore the 27 1/3 must be divided by 1/3 = 82. Therefore to get a 70 he needs a final score of at lest 82 on the final test.

For the 79 average he needs an additional 36 1/3 points. But again he only gets 1/3 of credit therefore the 36 1/3 must be divided by 1/3 = 109. 

Lets assume he needs a perfect score for the 79 average.