the answer is d thats what im choosing because i recall doing a similar problem to this
Answer:
7.5 lb/cu ft
Step-by-step explanation:
75 lb / 10 cu ft = 7.5 lb/cu ft
Let

be the number of rides Chandler takes in a month. Then the cost with the MetroCard is still $81, but the cost without the MetroCard is

. So we can set up an equation representing what we want: "The cost with a MetroCard of r rides in a month is less than the cost without a MetroCard." In equations,

Thus, at a minimum, Chandler must take 41 rides for his MetroCard to be cheaper than not having it.
1 quart = 32 ounces
2 x 32 = 64
$6.40 divided by 64 ounces
.10 per ounce