Question

date: _____________ per: __ homework : intro to sets; venn diagrams this is a 2 - page document! directions: define each set and classify it as a finite or infinite set. 1. the days of the week. 1. 2. odd numbers greater than 9. 2. 3. months with exactly 30 days. 3. 4. positive factors of 24. 4. 5. states that begin with the letter b. 5. 6. multiples of 7. 6. 7. if ( u = {2, 4, 6, 8, 10, 12, 14, 16} ) and ( a = {6, 10, 14} ), what is ( a )? 8. if ( u ) is the set of the numbers on a 6 - sided die and ( b ) is the set of numbers on a 6 - sided die that are greater than 3, find ( b ). 9. if the universal set contains natural numbers that are at most 25, and ( a ) is the set of multiples of 3 that are less than 20, define each set. ( u = ) ________________________________________________ ( a = ) ________________________________________________ ( a = ) __________________________________________________ 10. use the following sets to define each set below. ( a = {4, 7, 10, 14, 17, 20}, b = {1, 4, 9, 14, 20}, c = {2, 3, 7, 10, 17} ) a) ( a cap b ) b) ( b cup c ) c) ( a cup c ) d) ( a cap c ) e) ( b cap c ) f) ( a cup b )

Explanation:

Problem 1: The days of the week

The set of days of the week includes Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday. There are 7 elements, a definite number, so it's a finite set.

Odd numbers greater than 9 are 11, 13, 15, 17, ... and this sequence goes on infinitely as there's no largest odd number. So the set is infinite.

Months with exactly 30 days are April, June, September, November. There are 4 elements, a definite count, so it's a finite set.

Answer:

Set: {Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday}; Classification: Finite set

Problem 2: Odd numbers greater than 9