There are two sets of data: the mean of the first set is 15, and the mean of the second set is 20.
One of the pieces of data from the first set is exchanged with one of the pieces of data from the second set.
As a result, the mean of the first set of data increases from 15 to 16, and the mean of the second set of data decreases from 20 to 17.
What is the mean of the set made by combining all the data?
A
B
C
D
E