Plz someone me with questions 1 and 2 bcz i’m stressing out and don’t understand it.

The product of two negative rational numbers is always zero sometimes zero never zero

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

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25