## Adorkable 3 years ago Compound Interest Joshua invests $2000 at an annual interest rate of 6.05%, compounded semi-annually. He needs to make his investment grow to$2400 determine the time this will take. Please explain and show work thanks!

1. cammyabbo

you will use the compound interest formula, semi annual is twice a year

2. cammyabbo

you're given the amount of the investment plus interest, so all you do is solve for t, which is years

3. cammyabbo

$2400=2000(1+\frac{ r }{ c })^{tc}$

4. cammyabbo

r=annual rate (0.0605) c=times compounded per year (2) t=time in years (solve for t)