10 ! 2000 at 9% for 6 months (convert months to years)

So 6 months would be .5 years

9% of 2000 is 180
you get that from doing this:
.09×2000=180

Since we have to pay 180 for 6 months/.5 years

we need to multiply 180 by .5

180×.5=90

$90