Math
posted by Michele .
Please help
Brent washes 6 cars in 72 minutes. How many minutes does it take Brent to wash one car?
Approximately 4 out of every 10 students at Marc's college live on campus. The college has 3,000 students. How many of them live on campus?
The electricity costa of a business decresed from 11,000 one yeasr to 10,000 the next. To the nearest whole percent,what was the rate of decrease?

1/6 of 72 = ?
(4/10) x 3,000 = ?
(1000/11,000) x 100 = 100 x (1/11) = ?