SOLUTION: Which is a better deal: A grapefruit that is 5 cm in radius that costs 22 cents or a grapefruit that is 6 cm that costs 31 cents? Compute the cost per cubic cm for each grapefruit

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Question 329107: Which is a better deal: A grapefruit that is 5 cm in radius that costs 22 cents or a grapefruit that is 6 cm that costs 31 cents? Compute the cost per cubic cm for each grapefruit to answer this question.
Found 2 solutions by Fombitz, checkley77:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
For a sphere,
V=%284%2F3%29pi%2AR%5E3
.
.
.
C1=0.22%2F%28%284%2F3%29pi%2A5%5E3%29=0.00042cents/cc
C2=0.31%2F%28%284%2F3%29pi%2A6%5E3%29=0.000343cents/cc
.
.
.
The larger grapefruit is the better deal because it has the lower cost per volume.

Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
V=4/3PIR^3
V=4/3*3.14*5^3
V=4/3*3.14*125
V=4/3*392.5
V=1,570/3
V=523.33 CM^3 ANS. FOR THE VOLUME OF THE 5 CM. GRAPEFRUIT.
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V=4/3*3.14*6^3
V=4/3*3.14*216
V=4/3*678.24
V=2,1712.96/3
V=904.32 CM^3 ANS. FOR THE VOLUME OF THE 6CM. GRAPEFRUIT.
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523.33/22=28.79 CM^3 PER CENT FOR THE 5 CM GRAPEFRUIT.
904.32/31=29.17 CM^3 PER CENT FOR THE 6 CM GRAPEFRUIT.
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BUY THE BIGGER GRAPEFRUIT.