Data Sufficiency

For a certain company X, the average daily payroll for each 30-day payroll cycle is the average (arithmetic mean) of the daily payroll totals for each of the 30 days. During the first part of a recent 30-day payroll cycle, the daily payroll was a constant $5,750. When a new employee was hired during this 30-day cycle, the total payroll for each day rose by $280. If the new daily payroll total remained constant for the remainder of the cycle, what was the average daily payroll for the 30-day cycle?

(1) The new employee was hired on the 11th day of the payroll cycle.

(2) The average daily payroll was $5,890 through the first 20 days of the cycle

How is B self sufficient ?

OA D