By definition, the mode/s is/are the value/s that appear most frequently in a data set.
Ordering the given data set, we have:
[tex]40,40,42,48,54,61,65,72,76,78,84,84.[/tex]We see that the most repeated values are 40 and 84. We conclude that the modes are 40 and 84.
Answer40 and 84