Can some one help me in getting the questions from 1-200.
Almost a repeat post, but just meant to drive home the point 😉
The following thread will become sticky by the afternoon. Carry on the discussions from #201 onwards here...
i am getting d answer as D none of the fore going
chek dis out and tell me where it went wrong (if it did)
let "a" be d people who only study at home
" c" be d poeple who only attend classes
" b" people who attend classes and study at home
"d" who do nothing
now from the question a set of equations can be framed
(c+d)+(a+d) = 4/3(a+b+c+b)
b= 1/2(d) and a+c=2/3(b) we need to find out what d+b is
solving we get a=5/4(d) b=1/2(d) c=7/4(d) and a+b+c+d=300
therefore b+d = 100
which is not in the options
now what is going wrong in this
ANS - 180
a = students who only study at home
b = students who only attend classes
c = stduents who do both
n = students who do neither
according to the Q,
a+b = 2c ...1
c = n/2 ...2
a+b+n = 4/3*(a+b+c)
b = 7/5*a
a+b+c+n = 300 ...3
frm 1,2 n 3 ->
c = 60, n = 120
so reuired answer -> c+n = 180.
hi folks ..this is my first post
todays question :
In a certain class of 300 students , the number of students who either do not study at home or do not attend classes is a third more than of those who either study at home or attend classes. the number of students who do not study at home but attend classes is two fifths more than those who study at home but do not attend classes, while the number of students who
study at home as well as attend classes is half of those who neither study at home nor attend classes. If the number of students who only study at home or only attend classes is a third less than those who do either, then how many students who either do neither or do both?
(a) 150 (b) 180 (c) 210 (d) none of the foregoing
my answer is (b)
the equation we get is :
3x = 4z + R + Y
x+ Y + z + R = 300
solving these : x = 4z + R + y / 3 = 2z
=> 2z = R + y
=> 3z + x = 300
=> 5z = 300
=> z = 60 .
therefore x +z = 180 .
where x = no of persons which neither study at home and neither attend classes .
y = no of persons attending classes only
r= no of persons studying at home only
z = no of persons doing both .
a = students who study at home
b = students who attend classes
z = students who do both the above
x+y = c = students who neither study nor attend the classes
Accroding to the conditions in the question, we have 5 equations
(1) c = 4*(a+z+b)/3
(2) b = 7*b/5
(3) z = 0.5*c
(4) a+b = 2*(a+z+b)/3
(5) c+z+a+b = 300
Using equations (3), (4) and (5), we get,
z = 60
c = 120
Our answer = z+c = 180
P.S - We don't require equations (1) and (2) to solve this question.
180 it is
simple ques on venn diagrams
a = study at home only
b = both
c = attend classes only
d = neither
a+ b + c + d = 300
a + c = 0.67 ( a + b + c )
b = d / 2
only these 3 r enuf
to get d = 120 b = 60
hence ans = 180
My answer : (b) - 180
Intersection =(x+y)/2 where x,y are the number of people doing only attending classes and studying at home.
From the last equation (x+y)'=120 ,from third eqn.,(x+y)'=2(intersection).
So Intersection +(x+y)'=120+ 120/2 =180