You already know the value of 1 feet, right?
Now,
To convert 30 feet into meters, simply multiply the number 30 with the value of 1 feet. (i.e., 0.3048)
30 feet = 30 × value of 1 feet
On multiplying the number 30 with 0.3048, you’ll get the answer of 30 feet into meters.
See this,