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  • sumit goel
  • 449 karma
There are three classes X,Y and Z. Average of class X is 83. Average of Class Y is 76. Average of class Z is 85. Average of class X and Y is 79, average of class Y and Z is 81. Find average of three Classes.
a.81 b.81.5 c.82 d.84

though i dont think its the right place to reply...u can use quant thread for these type of queries....

btw my take goes like this
X: 83
Y: 76
Z: 85
X+Y: 79
Y+Z: 81

ths imples n(X):n(Y) = 3:4
n(Y):n(Z) = 4:5

therefore aggregate of three classes will be:
= 3(83)+4(76)+5(85)/ 3+4+5
= 81.5 plz check out.
tarun g Says
can someone explain the logic behind this question?


A couple can be chosen in 5C1 way the left people will be arranged
Therefore 5760*5*2*9

but i am not wnt some one to check
  • 1 Like  
i am getting 1/1016 ...OA kehta hai pi/2040......
kya gadbad hai...OA yaa humari approach.....

obvious it will be OA....i hav rechecked and sorry to say pie cant come in answer. as its asking for ratio...i have wrongly put pie in my previous post
consider a circle with unit radius. There are 7 adjacent sectors in it s1....s7 such that there total area is 1/8 of the area of the circle. The area of the j th sector is twice that of the j-1 th sector for j = 2,3,4..7. Find the ratio of s1 to the circle.

1/8*127 = 1/1016 ??
If there are 209 students..
P says 133 are females.
Q says 132 are females.
Clearly, Q is a female.

If there are 209*2 students, P would say there are 266 females and Q would say there are 264. Clearly, this data is inconsistent.
So, I and III are correct.

@N(P+K) bhais: abhi shikayat karta hoon Chill sir se

bhai, class mates means excluding the speaker so the students will be u r right...but OA will becum wrong
Two classmates P and Q have a conversation as below.
P: 7/11 of my classmates are females.
Q: That is interesting, because 12/19 of my classmates are females.

Assuming that both P and Q speak the truth, which of the following statements are true?
I. Q is a female.
II. P is a female.
III. There are a total of 209 students in the class.

(1) Only II and III
(2) Only I
(3) Only I and III
(4) None of the statements are true.

noblekalra Says
only I and III my take....

OA should be (2) Only 1......want my approach??
A father is aged three times more than his son Ronit. After 8 years, he would be two and a half times of Ronit's age. After further 8 years, how many times would he be of Ronit's age ?
a). 2 times
b). 5/2 times
c). 11/4 times
d). 3 times

F = R + 3R
(F+ = 2.5(R+

frm this u can find out the solution
10C3 ways

it is saying less then 7 in every case, so dont u thnk we should take max as 6 and OA becum 6C3 = 20.
There are 4 subjects namely a,b,c,d in an examination. In how many ways, a student can score a total of exactly 21 where all the individual subject scores are below 7?

*padke bachha question laga tha, par kuchh to gadbad hai bhailog.

20 aa raha hai bhai mera to.....
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Q. No. of integral solution of x + |y| + z = 10 ??

1. 402
2. 304
3. 202
4. 502

1. 402, whats d OA?