9. Amanda invests $400 in an account that earns 3.2% interest compounded annually. She wants to keep the investment until she doubles her money. How long will it take to reach that goal? A. 20 years
B. 23 years
C. 25 years
D. 28 years​

Point r divides in the ratio 1 : 3. if the x-coordinate of r is -1 and the x-coordinate of p is -3, what is the x-coordinate of q? a. b. 3 c. 5 d. 6 e. -9

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25