There are 300 junior high school students participated in school's math olympics.80 students registered in math trail,98 students registered in amazing race and 42 students registered in both math trail and amazing race.

a.How many students registered in math trail only?
b.How many students registered in amazing race only?
c.How many students did not registered both math trail and amzing race?

Solutions:
STEP 1:

STEP 2:

STEP 3:​