Hello,
If 1/3 of 480 students have traveled overseas, that means (1/3)(480) = 160 students have traveled overseas.
If 15% of the 160 students have been to Australia, then 1 - (0.15) = 0.85 = 85% of the 160 students have not been to Australia.
85% of 160 students = (0.85)(160) = 136 students have not been to Australia.
136 students have not been to Australia.
Hope this helps!
