Answer:
1. 36 days, 2. $8,680
Explanation:
1. We know that 12 men can do the work in 72 days, so if you add double the men, it will take half the time. Half of 72 is 36, so our answer is 36 days.
2. If $7,000 is borrowed, that person owes $7,000 so far, but they keep it for 4 years with an annual interest rate of 6%. To solve this, we need to find 6% of 7,000. To do this, we multiply 7,000 by .06. That gets us 420. Now, we multiply 420 by 4. That gets us 1,680. Now, we add 1,680 and 7,000. That gets us 8,680. That means the final amount owed is $8,680.