C because 4 1/3= 13/3
Then (13/3)x9= 39
Lastly 39+4= 43
In four weeks, he would be able to type 35 words a minute. See how it goes up two words per week. He started with 27 words, then after one week, it was 29, and after two weeks, it was 31, so after three weeks, 33, and in four weeks, 35. See the pattern? It counts by twos.
The answer 5 times 20 equals 100
Average minute per commercial
30/4 =7.5
For 10 commercials it will be
10*7.5 = 75 minutes