We don’t know whether the organization hired workers from places other than Europe, Asia and Africa. Therefore, statement (1) alone is insufficient. The correct answer would be among B/C/E.
This only tells us that the hired members are from Europe, Asia and Africa. There is no mention about the possible break-up across these locations. Therefore statement (2) alone is also insufficient.
The correct answer would be between C/E.
Statement (1 & 2)
Statements (1) and (2) together imply that 100 workers are divided in the ratio 3:1:1 between Europe, Asia and Africa. Let the number of workers in Europe be x.
We get, 3 x + x + x = 100
5x = 100
x = 20
Workers from Europe = 3x = 3(20) = 60
Therefore, both statements together are sufficient.