Answer:
A is the answer- Density = number of books over volume of shelf
Step-by-step explanation:
Density is mass/volume, so the number of books is the mass and the volume of the shelf is the volume for this equation.
A / B
= 80 / 8
= 10
Therefore the answer is 10
Find what the sum of the #s could be by multiplying 15*4 since there's 4 #s . 15*4=60 so the sum of the 4 #s is 60


Hence there is no such natural numbers exist.