Answer:
D, 20:30
Step-by-step explanation:
At first glance, this does not seem like the correct ratio. But I'll spare you a long intro and get into it:
20:30: Divide both of them by 10
=2:3
2 x 12:3 x 12
24:36
Hope this helps!
Answer:
Nobody likes a short, one-word-answer. Let’s make sure other people understand everything.
Step-by-step explanation:
By lisa Simpson
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
.
$1.52 is the total cost. Good luck and have an amazing day!