Ineed plz no one in my class understands it? also tell me the equation and the right answer

The probability that a college student belongs to a health club is 0.3. the probability that a college student lives off-campus is 0.4. the probability that a college student belongs to a health club and lives off-campus is 0.12. find the probability that a college student belongs to a health club or lives off-campus. tip: p(a or b) = p(a) + p(b) - p(a and b) 0.54 0.58 0.70 0.82

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Rose bought a new hat when she was on vacation. the following formula describes the percent sales tax rose paid b=t-c/c