Calculate the density of... An object that has a mass of 8 grams and a volume of 4 cubic cm
An object that has a mass of 16 grams and a volume of 8 cubic cm

Explain whether or not it is possible that both objects are made of the same material

Please dont just give the answer explain how you got it cuz I have a test on Monday and I dont really understand this.

The yearly amounts of carbon emissions from cars in belgium are normally distributed with a mean of 13.9 gigagrams per year and a standard deviation of 5.8 gigagrams per year. find the probability that the amount of carbon emissions from cars in belgium for a randomly selected year are between 11.5 gigagrams and 14.0 gigagrams per year. a. 0.340 b. 0.660 c. 0.167 d. 0.397