The total marks obtained by a student in Physics,
for Mathematics together ore 120 more
than the marks obtained by him in Chemistry. What
is the aug, marks obtained by him in Physics &
Mathematics for together?
Answers
Step-by-step explanation:
Let us prepare a chart of the 100 students using the data from the bar graph.
Marks Number of Students
0 − 9 27
10 − 19 12
20 − 29 20
30 − 39 24
40 − 49 17
(i) Number of students with less than 20 marks = 27 + 12 = 39
∴ Required sum to buy the workbooks = Rs. 5 × 39 = Rs. 195
(ii) Highest marks group = 40 − 49
Number of students in this marks group = 17
∴ Required money to distribute the prize = Rs. 10 × 17 = Rs. 170
(iii) Lowest marks group = 0 − 9
Number of students in this marks group = 27
∴ Number of problems that will be solved by the students per day = 5 × 27 = 135
(iv) (a) True
Explanation: Number of students in the marks group 40 − 49 = 17
Total number of students = 100
∴ % of students in the marks group 40 − 49 =17100×100%=17%
(b) False
Number of students in the marks group 10 − 29
= Number of students in the marks group 0 − 9 + Number of students in the marks group 10 − 19
= 12 + 20 = 32
(v) Number of students scoring less than 20 marks
= Number of students in the marks group 0 − 9 + Number of students in the marks group 10 − 19 = 27 + 12 = 39
(vi) Number of students scoring more than 29 marks
= Number of students in the marks group 30 − 39 + Number of students in the marks group 40 − 49 = 24 + 17 = 41
(vii) Number of students scoring between 9 and 40
= Number of students in the marks group 10 − 19
+ Number of students in the marks group 20 − 29
+ Number of students in the marks group 30 − 39
= 12 + 30 + 24 = 56
(viii) The highest marks group is 40 − 49.
Number of students in this marks group = 17
(ix) Number of students scoring more than 19 marks
= Number of students in the marks group 20 − 29
+ Number of students in the marks group 30 − 39
+ Number of students in the marks group 40 − 49
= 20 + 24 + 17 = 61
Answer:
Let marks obtained for
Math = x
Physics = y
Chemistry = z
Given, x + y = 120 + z _____(1)
Avg. marks of three subjects
= (x + y + z)/3
= (120 + 2z)/3
= 40 + (2/3)z
Conclusion:
The average marks obtained by the student = 40 + (2/3)z