Xander is 28 years old and is looking at selling his car and buy an electric motorbike. The electric motorbike costs 11,728 and he thinks he can sell the car for 2,430. He will borrow the remaining amount required to buy the motorbike. If Xander has to pay an interest rate of 7% p.a. compounded weekly, and he can afford to pay $100 a week, how long will it take Xander to pay off his loan? Enter your answer in weeks and with two decimal places (e.g. 12.34)