Question

According to the rule of 72, if the GDP of the Apex Federation is growing at 1.3% per year, its economy will double in approximately how many years?

A. 55 years
B. 17 years
C. 42 years
D. 41 years

Answer 1

55 years

Answer 2

72/1.3=55.38 so 55

Answer 3

55 Years

Answer 4

so wat did ya get on da test

Answer 5

yep

Answer 6

If you want to know when its economy will actually double, use this formula: Years = {log(total) -log(Principal)} / (log(1 + rate))
we'll say total =2 and principal =1 (for the doubling)
Years = {log(2) -log(1)} / (log(1 + .013))
Years = {log(2)} / (log(1.013))
Years = {log(2)} / (log(1.013))
Years = 0.3010299957 / 0.0056094454
Years = 53.6648414112 Years
Wow it's surprisingly close to the rule of 72 calculation.

Answer 7

So I guess you agree Perl?

Answer 8

so what now

Answer 9

now we can ... i dont know

Answer 10

@wolf1728 where did you get that formula, yes i agree

Answer 11

I got the formula from my website:
http://www.1728.org/compint2.htm
It has the interest formula solved for all 4 variables.

Answer 12

thanks guys @perl @wolf1728 @tyga24 @kaylamarie081

Answer 13

thanks wolf

Answer 14

u r welcome ar!3

Answer 15

yw

Answer 16

ur welcome