This math question can't be very hard, right?

[Harovan]

Originally posted by Big Crunch
The increase is what Asher wrote. The cumulative increase is what you have written. Not sure which Monk was after though.

Well, he wrote total increase...

[Dauphin]

Edit:

Actually that was wrong and forever immortalised in the following post.

[Harovan]

Originally posted by Big Crunch

SUM(n from 0 to 9)(1.15n) - SUM(n from 0 to 9)(1)

or

1/r[1 + 1/(1-r)ⁿ]

Where r is the % increase each year and n is the number of years.

Please be merciful with me, it's 1:45am, and I have digged my formula books very deep under.

[Monk]

Okay, I'm sorry if I've been unclear on some points. The task was to compare the 1978 and 1987 numbers - that is, to find out how many percent constituted the total increase from 1978 to 1987 assuming a 15% increase every year. I think the answer would have to be 22.5%.

[Asher]

I assumed what he was looking for was equivalent to compound interest...

I don't know if that's what he's looking for, but that's how I interpreted it.

[Guest]

1
11
21
1211
111221
312211
13112221
1113213211
31131211131221
way too classic by now