How can help me with this? Advens Math 6 grade

Answer:
200 students
Step-by-step explanation:
Let's say there are n teens in total.
Then 15% of n should be 30, i.e.:
n * 15 / 100 = 30 =>
n = 30 * 100 / 15 = 200.
You can draw two number lines where 100 connects to 15 and 200 connects to 30.