What's 9/10 minus 2/5

1. if events a and b are non-overlapping events, how do you find the probability that one or the other occurs? 2. what does it mean if p(a or b) equals 1?

Which problem would you use the following proportion to solve for? 24/x=40/100 a. what is 40% of 24? b. what percent is 24 of 40? c. twenty-four is 40% of what number? d. forty percent of 24 is what number?

The number 72 lies between what perfect squares