Frequency, Period, and Amplitude

Frequency: The number of vibration in 1 second.
Period: The number of time needed to achieve a 1 full vibration.
Amplitude: The distance between the maximum position of a vibration and the balanced position of a vibration.

The SI unit for frequency is Hz ( Hertz)
While the SI unit for a period is s (Second)

n: The number of motion of a vibration       t: Time
Formula of frequency: n/t
Formula of period: t/n

Question
1. What is the frequency: 15 vibration --> 3 second?
Answer:
F: n/t
F: 15/3
F: 15÷3= 5 Hz
So the frequency is 5 Hz

2. What is the Period: 3 vibration --> 12 seconds?
Answer:
P: t/n
P: 12/3
P: 12÷3= 4s
So the period is 4s