Answer:
b. 15 data items per minute
Step-by-step explanation:
Given,
The number of data he can input per minute at 9:00 AM = 3,
Since, he inputs data 2 data items faster each half hour,
So, the number of inputted data per minute at 9:30 AM = 3 + 2 = 5,
At 10:00 AM = 5 + 2 = 7,
At 10:30 AM = 7 + 2 = 9,
At 11:00 AM = 9 + 2 = 11,
At 11:30 AM = 11 + 2 = 13,
At 12:00 AM or at noon = 13 + 2 = 15,
Hence, his rate of inputting data at noon is 15 data items per minute.
Option 'b' is correct.