Question

In a class test sum of marks obtain by punnet in maths and science is 28 had he got 3 marks more in maths , 4 marks less in science the product of marks would have been 180 find his marks in 2 subjects

Answer 1

let's take maths marks =x

science = 28-x

given

(x+3) ( 28 -x - 4 ) = 180

(x +3) (24 - x ) = 180

24x -x^2 + 72 -3 x= 180

21x-x^2 =180- 72

21x -x^2 = 108

0=108- 21x +X^2

x^2 -21x + 108 = 0

x^2- 12 x -9 x +108 =0

x (x -12) - 9 (x -12)=0

(x -12 ) (x -9)=0



therefore

x-12=0 or x-9 = 0

so ,x= 12 or x= 9

maths =12

science = 28- 12=16

given

x +3 = 15 = marks of maths

16-4= 12 =marks of science

therefore,

marks of maths = 15

marks of science = 12

check,

15×12 =180