Give the step-by-step reasoning process and then the final answer. A choir was singing a song that involved 30 singers. In the first verse, only half of them sang. In the second verse, a third of the remaining singers joined in. How many people joined in the final third verse that the whole choir sang together?
In the first verse, 30 / 2 = 15 singers sang. In the second verse, 15 / 3 = 5 singers joined in. In the final verse, 30 - 15 - 5 = 10 singers joined for the whole choir to sing together.
The final answer: 10.