IV.
b. In a certain exam of grade ten, 75% students got high score in mathematics, 65%
students got high score in English. If 6% of them did not get high score in both
mathematics and English,
i. The percent of students who got high score in both the subjects.
ii. The total number of students who got high score either in mathematics or
in English if 300 students had attended the exam.
iii. Draw Venn-diagram to illustrate the above information.

Answer :

Answer:

1Let the percentage of students who got high scores in both mathematics and English be x

2The percentage of students who got high scores in mathematics is

75

%

75%−x

3The percentage of students who got high scores in English is

65

%

65%−x

4The percentage of students who did not get high scores in both subjects is

6

%

6%

5Set up the equation to find x :

(

75

%

)

+

(

65

%

)

+

+

6

%

=

100

%

(75%−x)+(65%−x)+x+6%=100%

6Solve for x :

75

%

+

65

%

+

6

%

+

=

100

%

75%+65%+6%−x−x+x=100%

146

%

=

100

%

146%−x=100%

=

146

%

100

%

x=146%−100%

=

46

%

x=46%

7Calculate the total number of students who got high score in either mathematics or English:

(

75

%

46

%

)

×

300

+

(

65

%

46

%

)

×

300

+

46

%

×

300

(75%−46%)×300+(65%−46%)×300+46%×300

=

29

%

×

300

+

19

%

×

300

+

46

%

×

300

=29%×300+19%×300+46%×300

=

87

+

57

+

138

=87+57+138

=

282

=282

8The total number of students who got high score either in mathematics or in English is 282

!!

“”

..

6% don't get high score in both, it means there are 94% students who have scored high.

i) 94=75+65-(no. of % of students who get high score in both)

94=140-x

x=46

ii) 100%=300 students

1% = 3 students

Now,

No. of students who get high score in either Maths or English = 94%×3

= 282 students

Thank You.

Other Questions