Answer:
I would take the loan.
Explanation:
I would take the loan because all around, $77 dollars is not that much money in itself. It would be fairly easy to pay your grandparents back eventually. Plus, if you have a strong desire and need for the item that costs $100, so much so that you would not mind paying technically $7 more to your grandparents in interest in total cost, it does not seem like so bad a decision. Overall, the interest rate would be 10%, which is quite low. In conclusion, I would definitely take the loan. :)