A student scored a total of 32 marks in a class test in maths and science. had he scored 2 marks less in science and 4 more in maths, the product of his marks would have been 253. find his marks in two subjects
Answers
Answered by
49
Let the marks in Maths be 'm' & marks in science be 's'
Given,m + s = 32
If he had scored 2 marks less in science, that is, (s-2) and 4 marks more in maths, that is (m+4), then the product equals 253
(s-2)*(m+4) = 253
Substitute s = 32-m for 's' in above equation
(32-m-2)*(m+4) = 253
(30-m)*(m+4) = 253
30m - m^2 - 4m + 120 = 253
26m - m^2 = 133
m^2 - 26m + 133 = 0
m^2 - 19m - 7m + 133 = 0
m(m-19) - 7(m-19) = 0
(m-7)(m-19) = 0
So m = 19 OR 7
If m = 19, s = 32-19 = 13
If m = 7, s = 32-7 = 25
Both the marks satisfy the given condition
So the marks are either (Maths=19, Science=13) or (Maths=7, Science = 25)
Given,m + s = 32
If he had scored 2 marks less in science, that is, (s-2) and 4 marks more in maths, that is (m+4), then the product equals 253
(s-2)*(m+4) = 253
Substitute s = 32-m for 's' in above equation
(32-m-2)*(m+4) = 253
(30-m)*(m+4) = 253
30m - m^2 - 4m + 120 = 253
26m - m^2 = 133
m^2 - 26m + 133 = 0
m^2 - 19m - 7m + 133 = 0
m(m-19) - 7(m-19) = 0
(m-7)(m-19) = 0
So m = 19 OR 7
If m = 19, s = 32-19 = 13
If m = 7, s = 32-7 = 25
Both the marks satisfy the given condition
So the marks are either (Maths=19, Science=13) or (Maths=7, Science = 25)
Answered by
73
Answer:
Step-by-step explanation:
Solution :-
Let marks in Mathematics be x.
And, marks in Science be 32 - x.
According to the Question,
⇒ (32 - x - 2)(x + 4) = 253
⇒ (30 - x)(x + 4) = 253
⇒ 26x - x² + 120 = 253
⇒ x² - 26x + 133 = 0
⇒ x² - 19x - 7x + 133 = 0
⇒ x(x - 19) - 7(x - 19) = 0
⇒ (x - 19) (x - 7) = 0
⇒ x = 19, 7
If x = 19, then,
Marks in Mathematics = x = 19
Marks in Science = 32 - x = 13
If x = 7, then,
Marks in Mathematics = x = 7
Marks in Science = 32 - x = 25
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