Geometric question (1 Viewer)

[Shoom]

lucia earns 25000, her wage increases by 5% every year find wage after 6 years

The common ratiio of a geometic series is 4 and the sum of first 5 terms is 3069 find the first term,

SHOW WORKING PLEASE.

 

[Azreil]

25000 * 1.05^6 = $33502.39

Sum = a(r^n - 1)/(r-1)
3069=a(4^5-1)/(4-1)
a=9
1st term = 9

 

[Shoom]

Why is it (r) 1.05 and not 0.05

 

[Azreil]

r = 1 + R
R = percentage given -- that's just how I remember it.

If you think about it though, multiplying by 0.05 would give a DECREASING answer whereas her salary is increasing.