Tell me if this is right if not than tell me the answer

7+(3n++8) what is the answer to this?

Acentral angle measuring 160 degrees intercepts an arc in a circle whose radius is 4. what is the length of the arc the circle formed by this central angle? round the length of the arc to the nearest hundredth of a unit. a) 4.19 units b) 6.28 units c) 12.57 units d) 12.57 square units

What 620000 divided by 10 to the third power