Find out how long it takes a $3100 investment to double if it is invested at 7% compounded quarterly, Round to the nearest tenth of a year. Use the formula A =
A) 10.2 years
B) 10.4 years
C) 10 years
D) 9.8 years

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.