Raj gives the senior secondary examination from C.B.S.E. Board. He took five papers in an examination having the same maximum marks for each. His marks were in the proportion 4 ∶ 5 ∶ 9 ∶ 10 ∶ 12. In all subject together he obtained 40% of the total marks .Then, the number of subjects in which he got: a) Less than 50% are 3. b) Less than 70% are 2. c) More than 60% are 3. Choose the correct option(s):
Raj gives the senior secondary examination from C.B.S.E. Board. He took five papers in an examination having the same maximum marks for each. His marks were in the proportion 4 ∶ 5 ∶ 9 ∶ 10 ∶ 12. In all subject together he obtained 40% of the total marks .Then, the number of subjects in which he got: a) Less than 50% are 3. b) Less than 70% are 2. c) More than 60% are 3. Choose the correct option(s): Correct Answer a only
Given∶
Marks were in the proportion = 4 ∶ 5 ∶ 9 ∶ 10 ∶ 12.
Raj obtained 40% of the total marks.
Formula Used∶
Basics of percentage and ratios.
Calculation∶
Let the marks scored in 5 subjects be 4x, 5x, 9x, 10x and 12x.
Total marks in all 5 subjects = 40x
Maximum marks of the 5 subjects = 40x/0.4
∴ Maximum marks in each subject = 40x/(0.4 × 5) = 20x
Hence percentage in each subject,
1st subject = (4x/20x) × 100 = 20%
2nd subject = (5x/20x) × 100 = 25%
3rd subject = (9x/20x) × 100 = 45%
4th subject = (10x/20x) × 100 = 50%
5th subject = (12x/20x) × 100 = 60%
∴ Number of subjects in which he got less than 50% are 3, less than 60% are 4 and less than 70% are 5. So, option 1 is correct.