Two workers, if they were working together, could finish a certain job in 12 days. if one of the workers does the first half of the job and then the other one does the second half, the job will take them 25 days. how long would it take each worker to do the entire job by himself?

If t17 = 3 (t5) in an arithmetic progression, find t1 in terms of d.

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?

The table showed price paid per concert ticket on a popular online auction site. what was the average price paid per ticket