in an examination 70 passed in history 50 in geography and 20 failed in both the subjects if 500 students

for 500 students=70+50-80=40%
for 100 students=100*500/40=1250
11 years agoHelpfull: Yes(8) No(1)
fail in both the subject=20%
pass in both the subject=80%
let x student appear in exam so 80% of x=500
so total no of appear student is 625
ans 625
11 years agoHelpfull: Yes(4) No(5)
80% passes of total students passed in both(100-20)
500=(70+50-80)% of x
x=1250
11 years agoHelpfull: Yes(2) No(0)
1000.... actually it is the simplest problem so there is no need to explain. hint is 50%
11 years agoHelpfull: Yes(1) No(0)
let no. of students be x
now, x= 0.20x + 0.70x + 0.50x - 500
x= 1250
11 years agoHelpfull: Yes(0) No(1)
Ans-625
20% fails in both Subject means 80% pass in both Subjects
so 80% of x is equals to 500(here x is total candidates appear in exam)
80x/100=500 i.e. x=625
11 years agoHelpfull: Yes(0) No(4)
@swati
the given percentage-pass is for each subject.Its not the percentage of students who got passed in the particular subject.So your equation is not valid.
I guess correct answer is 625
11 years agoHelpfull: Yes(0) No(4)

in an examination 70% passed in history.50% in geography and 20% failed in both the subjects. if 500 students passed in both the subjects, then how many candidates appear in exam?