Detailed Answer
Correct answer: (B)
The average collection period is 16 days, computed as:
Customers paying on day 10 = .70 x 10 days = 7 days average.
Customers paying on day 30 = .30 x 30 days = 9 days average.
Average collection period = 16 days
On average, 70% are outstanding for 10 days and 30% are outstanding for 30 days. By getting the weighted average of each group and summing them, the average collection period is determined.