Science 8 grade
posted by Thao .
A little aluminum boat (mass of 14.50g) has a volume of 450.00cm3. The boat is placed in a small pool of water and carefully filled with pennies. If each penny has a mass of 2.50g, how many pennies can be added to the boat before it sinks?

The boat will displace its mass in water, or 450 grams
n*2.5 + 14.5=450
solve for n. 
n=174.2 right?
How can you do that? 
you cant have .2 pennies,so it sinks on the 175th penny.