Answer:
160
Explanation:
If there were only 2 options, all the people who didn't pick one chose the other one.
So if 25% of the people voted for the aquarium the remaing 75% voted for the zoo.
Since three times as many people voted for the zoo, we can see that 120/3=40, so 40 people chose the aquarium.
To find the total number of students, we add 120 and 40 to get 160