Final answer:
Mary received 79.41% of the votes for class president when 135 out of 170 students voted for her.
Step-by-step explanation:
135 of 170 students voted for Mary to be their class president. To find what percent of the votes Mary received, we would use the following formula:
Percent = (Number of votes for Mary / Total number of students who voted) × 100%
Plugging in the numbers:
Percent = (135 / 170) × 100%
Percent = 0.7941 × 100%
Percent = 79.41%
Therefore, Mary received 79.41 percent of the votes.