Option B:

Solution:
Given sound level = 120 decibel
To find the intensity of a fire alarm:

where 
Step 1: First divide the decibel level by 10.
120 ÷ 10 = 12
Step 2: Use that value in the exponent of the ratio with base 10.

Step 3: Use that power of twelve to find the intensity in Watts per square meter.


Now, do the cross multiplication,




Option B is the correct answer.
Hence
.
Direct variation means their ratio is a constant
x/y is 9/45=1/5
so when x=2, y=5*2=10
Answer:
Step-by-step explanation:
56 1/2 because i did the math
Answer:
I'm not sure 710
Step-by-step explanation:
I'm not sure