Question

A dance instructor conducts annual workshops in which he holds sessions for basic learners and trainers. in a particular year, 2000 people attended the workshop. 1500 participated as learners and 800 as trainers. how many participated as only trainers?

Answer 1

n (A) = 1500 n (B) = 800 n (A union B) = 2000 n (A union B) = n(A) + n(B) - n(A intersection B) 2000 = 1500 + 800 - x Hence, x = 300. i.e., 300 people were both trainers and learners.  Hence only trainers = 800 - 300 = 500. Answer.