23.6% interest rate of "simple" interest (ie, non-NPV accounting). Pay 103 per month for 12 months. = $1236 per $1000.
or how do you know that this wasn't an "interest only loan" and you pay $103 in interest every month... and if you want to pay down any principle, then that would be anything that you pay above $103/month.
The problem is very clear when you read it carefully. Which is also one of the skills its trying to tease out. It is rated as a 5 out of 5 being the most difficult.