An iron ball has a density of 4 g/cm3. The volume of the ball is 15 cm3.
What is the mass of the ball?

Explanation:

m = mass

v = volume

d = density

The formula we use is

d = m/v

Multiplying both sides by v allows us to solve for m

d = m/v

d*v = m

m = d*v

Now plug in the given density (d = 4) and the given volume (v = 15) and simplify:

m = d*v

m = 4*15

m = 60 grams

Note how,

d = m/v

d = 60/15

d = 4

which helps confirm our answer

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)

ruth is 6 years old

step-by-step explanation:

6 + 24 = 30,   so 6/30 = .2  

if you do 1/5 it also equals .2, so that is the answer.