confusing simple interest question (1 Viewer)

[risole91]

Heres a question from my summary book, that i can't do.

what amount of principal must be invested at 5.8% p.a for it to grow to 15 000 in 8 years.

a. using simple interest
b. compound interest

i no simple interest is the easiest thing ever.
the answer in the BOB says 10245.91 for a.

im just confused as to how we get that with the information provided.

 

[undalay]

a)

A = P ( 1 + (0.058 x 8))
15000 = P ( 1.464)
P = 15000 / 1.464
= 10245.90

 

[shortcut]

argh! i hate credit and borrowing so so much, i have an exam tomorrow and am pretty much screwed for that part of it. sigh. can anyone explain reducing balance loans??
thanks!