Answer:
70 meters
Step-by-step explanation:
The first throw was the very first one described in the question and it was 8 meters long. So if the second throw is twice as far it would have been thrown 16 meters. The third throw was 5 meters less than the second throw, so 16-5=11. Now you add everything together, 8+16+11, which would equal 35 meters.You are not finished yet, you also have to account for spencer's run back, which means you have to multiply 35 by 2, so in the end you would have gotten that spencer ran 70 meters.