Adam was collecting bonus points toward a prize. The first and second weeks he earned 15 points each. The third and fourth weeks he earned 21 points each. When he turned in
his points on the last week, he found that 5 of the points weren't valid. How many points
did he receive credit for altogether?​

i leave the calculator work to you.

7. diameter 4 miles, circumference 4π miles

8. radius 0.2 miles, circumference 0.4π miles

[this is a bad problem because the actual radius of a car on the track is less than 0.2 miles so the answer is less than 0.4π miles]

9. radius 6 feet, circumference 12π feet

10. diameter 14 cm, circumference 14π cm

11. diameter 4.8 feet, circumference 4.8π feet

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.