Question

There are 40 students in a class and their results is presented as below:

Result (Pass/Fail)	Pass	Fail
Number of Students	30	10

If a student is chosen at random out of the class, find the probability that the student has passed the examination.
A. 0.75
B. 0.6
C. 0.45
D. 0.30

Answer 1

Hint: Here, the given problem is about to find the probability that the student has passed the examination. Firstly, we need to know what probability is and what is the formula to be used to solve this question. According to the given data, we should understand the data and solve according to the data given.

Complete step-by-step solution:
Let us start with knowing the concept of probability, we know that, It is the part of mathematics that deals with the outcome of a random event. The word probability means chance or possibility of an outcome. It explains the possibility of a particular event to occur.it is the ability to understand and estimate the possibility of a different combination of outcomes.
Uses of probability: It is important to figure out if a particular thing is going to occur in an event or not. It also helps us to predict future events and take actions accordingly. For instance, weather forecasting, agriculture, politics etc.
Formula to find out the probability is
Then the probability of an event, $$P={\displaystyle \frac{\text{Total number of favourable outcomes}}{\text{total outcomes}}}$$
Given data is there are 40 students in a class and their results are given
Total outcomes=40
Outcomes or trails which favour a student to pass = 30
The probability of the required event, i.e., the student has passed the examination$$={\displaystyle \frac{30}{40}}=0.75$$ .
The correct option is (A).

Note: The main concept of solving this question is the basic knowledge of probability. Understanding the question in the form of statements is the main criteria while solving these kinds of questions. Note that it is very rare for events happening to have the probability 1. Probability of an event lies between 0 and 1 for all the events.