In a class of 25 students,the probability that any one girls will be absent on an given day is 0.2. the probability of one of the boys being student 0.3.b calculate the probability of that all student present at Tuesday.
Answers
Answer: Probability of all students present at Tuesday is 0.56.
Step-by-step explanation:
Given that:
Total strength of the class is 25 students.
Probability of a girl being absent on a given day is 0.2.
Probability of a boy being absent on a given day is 0.3.
Probability of all student being present is asked.
Finding the probability of all being present:
First start with finding the probability of being present in case of girl and boy separately.
For girls:
Probability of a girl being present = Total probability - probability of being absent.
Probability of a girl being present = 1-0.2 = 0.8
For boys:
Probability of a boy being present = Total probability - probability of being absent.
Probability of a boy being present = 1-0.3 = 0.7
Combined probability:
Probability of all being present = probability of girls being present * probability of boys being present.
Probability of all being present = 0.8 * 0.7 = 0.56.
Hence, the probability of all student present at Tuesday is 0.56.
Concept
The total probability of an event occurring or not occurring is 1
Given
The total number of students in the class are 25.
Probability of a girl being absent on any given day is 0.2.
Probability of a boy being absent on any given day is 0.3.
Find
We need to calculate the probability of that all student present at Tuesday.
Solution
We know that,
The probability of a girl being present = Total probability - probability of girl being absent.
The probability of a girl being present = 1- 0.2 = 0.8
Similarly,
The probability of a boy being present = Total probability - probability of boy being absent.
The probability of a boy being present = 1- 0.3 = 0.7
Thus,
Probability of all being present = probability of girls being present * probability of boys being present.
Probability of all students being present = 0.8 * 0.7 = 0.56.
Hence, the probability of all students being present on Tuesday is 0.56.
#SPJ2