Question

40% of the students in a school are boys. In a particular school examination, attended by
all the students, only 20% of the girls passed, though 40% of all the students had passed.
Find the percentage of boys who passed the test.
1) 30
2) 50
3) 70
4) 28​

Answer 1

Answer: 70%

Step-by-step explanation:

Percentage of boys = 40%

Percentage of girls = 60%

20% girls passed the exam

= 20% of 60% students

= 20/100 × 60/100

= 12% students

So, 20% girls who passed the exam are 12% of students who passed the exam

Total 40% of students passed the exam

40% of students = x% of boys + y% of girls

40% students = x% boys + 12% students

x% boys = (40% - 12%) students

x% boys = 28% students

So, 28% of students who passed the exam are boys

Percentage of boys who passed the exam is then

z% of boys = 28% students

z% of 40% students = 28% students

z% = (28% students) / (40% students)

z/100 = 0.7

z = 70

Answer 2

Answer:

37.5% of boys are passed in the test.