Please answer this correctly

The multiplication property of zero states that the product of any number and 0 is 0. what must be true about either a or b to make ab=0

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

The evening newspaper is delivered at a random time between 5: 30 and 6: 30 pm. dinner is at a random time between 6: 00 and 7: 00 pm. each spinner is spun 30 times and the newspaper arrived 19 times before dinner. determine the experimental probability of the newspaper arriving before dinner.