Answer:
D) 13.62 kg/L
Explanation:
This problem can be solved by a simple rule of three.
The problem states that Mercury has a dansy of 30 lbs/L, and asks what is the density in kg/L. We have to convert from lbs to kg.
Each lb has 0.454 kg? How many kg are there in 30 lbs?
So:
1 lb - 0.454kg
30 lb - x kg
This means that mercury's density in kg/L is 13.62, letter D. Letter A is also 13.62, however it is not in the unit asked.