![subject](/tpl/images/cats/mat.png)
Mathematics, 13.03.2020 02:10 vrw28
Suppose a list A contains the 30 students in a mathematics class, and a list B contains the 35 students in an English class, and suppose there are 20 names on both lists. Find the number of students: (a) only on list A, (b) only on list B, (c) on list A or B (or both), (d) on exactly one list.
a. List A has 30 names and 20 are on list B; hence 30 - 20 =10 names are only on list A.
b. Similarly, 35 -20 =15 are only on list B.
c. We seek n(A U B). By inclusion—exclusion,
n(AU B) = n(A) +n(B)- n(A⋂ B) = 30+35 -20 —45.
In other words, we combine the two lists and then cross out the 20 names which appear twice.
d. By (a) and (b), 10 + 15= 25 names are only on one list; that is, n(A⊕ B)= 25.
![ansver](/tpl/images/cats/User.png)
Answers: 1
![](/tpl/images/ask_question.png)
![](/tpl/images/ask_question_mob.png)
Another question on Mathematics
![question](/tpl/images/cats/mat.png)
Mathematics, 21.06.2019 12:30
35 points, ! name one pair of congruent sides. a. segments pr and sv b. segments qr and st c. segments rp and ts d. segments pq and vs
Answers: 1
![question](/tpl/images/cats/mat.png)
Mathematics, 21.06.2019 15:30
Enter the missing numbers in the boxes to complete the table of equivalent ratios of lengths to widths. ? 18 8 ? 10 30 12 ?
Answers: 3
![question](/tpl/images/cats/mat.png)
Mathematics, 21.06.2019 16:30
Cassie is traveling 675 miles today to visit her brother and his family. so far, she has stopped for gas three times. at the first stop, she put in 7.1 gallons of gas and paid $23.79. at her second stop, she put in 5.8 gallons of gas and paid $19.08. and, at the third stop, 6.6 gallons and paid $20.39. at which stop did casey pay the most for gas?
Answers: 1
![question](/tpl/images/cats/mat.png)
You know the right answer?
Suppose a list A contains the 30 students in a mathematics class, and a list B contains the 35 stude...
Questions
![question](/tpl/images/cats/mat.png)
Mathematics, 22.05.2020 21:02
![question](/tpl/images/cats/geografiya.png)
![question](/tpl/images/cats/obshestvoznanie.png)
Social Studies, 22.05.2020 21:02
![question](/tpl/images/cats/istoriya.png)
History, 22.05.2020 21:02
![question](/tpl/images/cats/mat.png)
Mathematics, 22.05.2020 21:02
![question](/tpl/images/cats/istoriya.png)
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 22.05.2020 21:02
![question](/tpl/images/cats/istoriya.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 22.05.2020 21:02
![question](/tpl/images/cats/mat.png)
Mathematics, 22.05.2020 21:02
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/en.png)
![question](/tpl/images/cats/biologiya.png)
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/en.png)
![question](/tpl/images/cats/en.png)
English, 22.05.2020 21:02
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 22.05.2020 21:02