# Topscore 2 Question

#### Ruthless

10+ Year Member
In topscore 2 TS section #4. Shouldnt the answer be (c) 1000x and and not (b)? I think topscore got a mistake or I'm going thru a meltdown.

OP
R

#### Ruthless

10+ Year Member
This is the question just in case u dont have topscore

If a eukaryotic cell has a diameter or 10x that of a bacterial cell, proportionally how much more surface area does the eukaryotic cell have?
a. 10 times the surface area
b. 100 times the surface area
c. 1000 times the surface area
d. 10000 times the surface area

#### nze82

This is the question just in case u dont have topscore

If a eukaryotic cell has a diameter or 10x that of a bacterial cell, proportionally how much more surface area does the eukaryotic cell have?
a. 10 times the surface area
b. 100 times the surface area
c. 1000 times the surface area
d. 10000 times the surface area
Cells are assumed to be spherical. The surface area of a sphere is 4Pr^2.
Now, the problem says that the diameter of the eukaryotic cell is 10x that of the prokaryotic cell. So:
r(Eu) = 10r(pro)

Now, compare the ration of the surface areas:

A(Eu) : A(Pro) = (10r(pro))^2 : r(pro) = 100

OP
R

10+ Year Member
gotchya!