Abook store was selling 5 books for $27.75. online the you could buy 6 books for $32.16. which place has a lower unit price

27.75/5 = $5.55 per book
32.16/6 = $5.36 per book
The online store is the cheapest because it has the lowest unit rate

1. If it is intersection then it SHOULD be included in both the sets right? Now we know that odd numbers from 1-100 but the second set are multiples of 5 from 50-150! So we mainly need to look for common numbers which are ODD and are a MULTIPLE OF 5 BETWEEN 50 - 100!! So A={51,53,57,59,6199} B={55,60,65,7095} [We stop till 100 because set A has no such element] So what is A ∩ B here? A ∩ B = {All odd numbers and multiples of 5 between 50 - 100}