math
posted by Meg .
Which is the best investment for three consecutive years?
a. A growth of 5% followed by a growth of 10% followed by a growth of 15%
b. A growth of 15% followed by a growth of 10% followed by a growth of 5%
c. Three years of growth at 10% per year.


Do you have to add them all together or multpily?

did you not look at the solution I gave in the link ?

yes, I saw that, but how do I get the answer on each line to compare them. Do I multiply each line, or add them.

first one:
you multiply them, brackets mean multiplication
1.05(1.1)(1.15)
= 1.05 x 1.1 x 1.15 = 1.32825
so that is an increase of 32.825% 
1.32825 is what I got for the b and 1.331 is what I got for c so I guess the answer would be c

correct
c) has the largest number, thus the largest growth