In a class of 30 students, 9 have a brother and 17 have a sister. There are 7 students who have a brother and a sister. What is the probability that a student chosen randomly from the class has a brother and a sister?

Respuesta :

Answer:

Given are..

30

9

17

7

Operation to use..

Addition and Subtraction

Solution:

9 + 17 = 26

30 - 26 = 4

4 + 7 = 11

so in that case there are 11 student chosen randomly from the class has a brother and a sister.

Answer:

26/30=13/15 is the probability that a student chosen randomly from the class has a brother and a sister.

Step-by-step explanation:

both brother and sister=7

Brother is 9

Sister is 17

probability of brother and sister={9/30}+{17/30}=26/30