Official Quant thread for CAT 2013

MBA CAT 2024
27888
@ananyboss said:
Q -- There are 42 students in a hostel, Due to admission of 13 new students, the expense of the mess increases by Rs 31. per day. While the average expenditure per head diminished by Rs 3. What was the original Expenditure of the mess ?ANs - 633.23Please Tell the approach !
let total expense be x
x/42 - x+31/55=3
x comes as 633.23
27889
@albiesriram said:
1/_/2 h kya ?? apologies if wrong on my way back to office
27890
@albiesriram said:
is it b?
not sure.. though..
27891
@ChirpiBird OA

OS:-

27892
@albiesriram said:
@ChirpiBirdOAOS:-
yea... i also drew a square outside the bigger circle. then equated the length of diagonal :)
27893
@Tusharrr said:
A cube has 8 vertices. For each pair of distinct vertices, we connect them up with a line segment. There are 28 such line segments. For each of these 28 line segments, we mark the midpoint. How many distinct points have been marked as the midpoints?
mid-points of edges = 12
mid-points of faces = 6
mid-point inside cube = 1
Answer = 19 ?
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27895
@Tusharrr said:
A cube has 8 vertices. For each pair of distinct vertices, we connect them up with a line segment. There are 28 such line segments. For each of these 28 line segments, we mark the midpoint. How many distinct points have been marked as the midpoints?
it will be 19 ??
6+12+1=19
27896
@albiesriram said:
12/15=4/5?
27897
@albiesriram said:
Draw a table and we can see that 4+3+3+1+1=12 out of 6C2 ways
Hence 4/5
27898
@albiesriram said:
d? 4/5

3C2 out of 6C2 donot speak same lang.
3/15 = 1/5

so the pair which do speak common lang = 1-1/5 = 4/5
27899
@albiesriram said:
taking AB = -k and BC = 1 and proceeding ,

OA = (k^2+1)^3/k^2
27900
@albiesriram said:
H -> E and G
I -> G and S
JP -> F and S
K -> G and F
L -> F and E
M -> S and E

Common language pairs = HI, HK, HL, HM, IJP, IK, IM, JPK, JPL, JPM, KL, LM = 12 pairs

So, P = 12/6C2 = 12/15 = 4/5 ?
27901
@albiesriram said:
4/5 ?

12/6c2 = 12/15 = 4/5
27902
@ChirpiBird said:
d? 4/53C2 out of 6C2 donot speak same lang.3/15 = 1/5so the pair which do speak common lang = 1-1/5 = 4/5
Why didn't I!?
27903
@ all OA .

Solution:-

27904

Basic wala..

27905
@albiesriram said:
Basic wala..
16 ?

5 ---> 1 way
1 1 1 1 1 ----> 1 way
1 1 1 2 ---> 4!/3! ----> 4 ways
1 1 3 ---> 3!/2! ----> 3 ways
1 4 ----> 2! ---> 2 ways
2 2 1 -----> 3!/2! ----> 3 ways
2 3 ----> 2! ----> 2 ways

1 + 1 + 4 + 3 + 3 + 2 + 2 = 16 ways
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@albiesriram said:
Basic wala..
16 ways
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