The following table given the marks scored by 50 students in a 100 marks test of Mathematics.
`{:("Marks",0-20,20-40,40-60,60-80),("No of "3,12,18,10,7),("students",,,,):} `
A student is selected randomly from the class.
Find the probability that the selected student.

Answer

To solve the problem, we will follow these steps:

### Step 1: Organize the Data
We have the following data from the table:

| Marks | Number of Students |
|-----------|--------------------|
| 0 - 20 | 3 |
| 20 - 40 | 12 |
| 40 - 60 | 18 |
| 60 - 80 | 10 |
| 80 - 100 | 7 |

### Step 2: Calculate Total Number of Students
We need to find the total number of students. We will sum the number of students in each category.

Total Students = 3 + 12 + 18 + 10 + 7
Total Students = 50

### Step 3: Find Probability of Selected Student Scoring Less than 40 Marks
To find the probability that a randomly selected student scored less than 40 marks, we need to consider the categories that fall below 40 marks, which are:

- 0 - 20: 3 students
- 20 - 40: 12 students

Total students scoring less than 40 = 3 + 12 = 15

Now, we can calculate the probability:

Probability (Less than 40) = (Number of students scoring less than 40) / (Total number of students)
Probability (Less than 40) = 15 / 50
Probability (Less than 40) = 3 / 10

### Step 4: Find Probability of Selected Student Scoring 60 or More Marks
Next, we find the probability that a randomly selected student scored 60 marks or more. The relevant categories are:

- 60 - 80: 10 students
- 80 - 100: 7 students

Total students scoring 60 or more = 10 + 7 = 17

Now, we can calculate the probability:

Probability (60 or more) = (Number of students scoring 60 or more) / (Total number of students)
Probability (60 or more) = 17 / 50

### Final Answers
1. Probability of a student scoring less than 40 marks = 3/10
2. Probability of a student scoring 60 or more marks = 17/50

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