The data set 3, 3, 5, 5 and 8 has one of its two fives removed, leaving 3, 3, 5 and 8. What is the mode of the reduced data set?

Explication

After the removal, 3 still occurs twice while 5 and 8 occur once each, so 3 alone reaches the highest frequency and is the single mode. Keeping 5 as a mode carries over the tie from the original set, but a mode describes the data as they now stand, and the removal broke that tie.