There are some pupils rehearsing for a performance in an auditorium.
1/2 of the pupils are practicing singing and 1/6 of them are doing dance steps.
The remaining 72 pupils are playing their musical instruments.
(a) How many pupils are there in the auditorium?
(b) If there are 24 more girls than boys rehearsing for the performance, how many girls are there in the auditorium?