Jung-Su's father gave him $144. Jung-Su bought 4 books, each of which cost $9. How much money does Jung-Su have left?

Based on the figures as marked, /\rqs = —

Due to financial difficulties the owner of 4 skateboard stores is going to close 2 of his stores. based on the money earned at each store, which two stores should remain open?

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?