Official Quant thread for CAT 2013

MBA CAT 2024
25948
@scrabbler said:
67.Assuming that a dart is guaranteed to hit the board, the areas of the circles are in ratio 1 : 3 : 5 : 7 (as in previous question). Chances of 10, 7, 5, and 3 are therefore 1/ 16, 3/16, 5/16, 7/16.For a total of 10, we need 3, 7 or 5,5 or 7,3 i.e 7/16 * 3/16 or 5/16 * 5/16 or 3/16 * 7/16 = (21 + 25 + 21)/256 = 67/256regardsscrabbler
Hail King Scrabbler.......
25949
@abhishek.2011 said:
wellab comes as _/1540/39ad comes as _/351/15area=ab*ad=36
bhai please find time to write how did ab and ad come. (if possible)
25950
@albiesriram said:
7/12 i think
just use of similar triangles area side ratio concept
25951

may i post more?

25952
@albiesriram said:
may i post more?
yes boss......
25953
@albiesriram said:
bhai please find time to write how did ab and ad come. (if possible)
bhai look
as e is a point inside rectangle
ed^2 + eb^2 = ae^2 + ec^2
ed comes as 4

now
as angle dec = 180 - angleaeb
cosdec = -cosaeb ------1)
taking cos on both sides
cos dec = 4^2 + 8^2 -ab^2/2*4*8
similarly cos aeb =1^2+7^2-ab^2/2*1*7
putting this in 1)
ab comes as _/2160/39
similarly in triangle ade and bec
cos ade = -cosbec
doing the same
ad=_/351/15
multiplying the two gives 36
25954
@albiesriram said:
may i post more?
yup bhai go ahead
25955
@scrabbler said:
67.Assuming that a dart is guaranteed to hit the board, the areas of the circles are in ratio 1 : 3 : 5 : 7 (as in previous question). Chances of 10, 7, 5, and 3 are therefore 1/ 16, 3/16, 5/16, 7/16.For a total of 10, we need 3, 7 or 5,5 or 7,3 i.e 7/16 * 3/16 or 5/16 * 5/16 or 3/16 * 7/16 = (21 + 25 + 21)/256 = 67/256regardsscrabbler
_/\_
bhai probability sikha do mujhe nhi aati yar
25956
25957

In a regular octagon

1.how many pairs of parallel diagonals are there?
1. 4 2. 8 3. 12 4. 16
2. if there is a regular polygon of 20 sides, how many diagonals originate from one vertex?
1.17 2. 18 3. 19 4. 20

p.s. second question ke liye approach plz
25958
@Highway66 said:
In a regular octagon1.how many pairs of parallel diagonals are there? 1. 4 2. 8 3. 12 4. 162. if there is a regular polygon of 20 sides, how many diagonals originate from one vertex?1.17 2. 18 3. 19 4. 20p.s. second question ke liye approach plz
i guess 2nd wala is 17.. if you consider any point it wont make a diagonal with the adjacent lying points. so totally 3 points should be neglected hence 17.. the point will make diagonals with all the 17 points
25959
@Highway66 said:
In a regular octagon1.how many pairs of parallel diagonals are there? 1. 4 2. 8 3. 12 4. 162. if there is a regular polygon of 20 sides, how many diagonals originate from one vertex?1.17 2. 18 3. 19 4. 20p.s. second question ke liye approach plz
second questions is a sitter.
leave the adjacent vertices, all the others will form diagonals. hence 17
25960
@Highway66 said:
In a regular octagon1.how many pairs of parallel diagonals are there? 1. 4 2. 8 3. 12 4. 162. if there is a regular polygon of 20 sides, how many diagonals originate from one vertex?1.17 2. 18 3. 19 4. 20p.s. second question ke liye approach plz
1. ... 16 pairs?
2.. 17?


damn it, 1> 8. didnt divide by2. 😞 :splat:
25961
@albiesriram said:
2+_/3/2
25962
@Highway66 said:
In a regular octagon1.how many pairs of parallel diagonals are there? 1. 4 2. 8 3. 12 4. 162. if there is a regular polygon of 20 sides, how many diagonals originate from one vertex?1.17 2. 18 3. 19 4. 20p.s. second question ke liye approach plz
1)8?
25963
@albiesriram said:
(2+rt3)/2?

regards
scrabbler
25964

This one is a nice ques:


A pencil, eraser and notebook together cost Rs 100. the notebook cost more than two pencils. three pencils cost more than four erasers and three erasers cost more than one notebook. Answer the questions given that cost are positive, non-zero, integers.
1) The cost of pencil is
a) 27 b) 26 c) 28 d) data insufficient
2) if u paid the shopkeeper Rs 210 for 2 notebooks, 3 pencils and 1 eraser, how many change would he return
a) 3 b) 5 c) 7 d) data insufficient

25965
@albiesriram said:
option C?
25966
@ChirpiBird said:
option C?
teek hai.
25967
@albiesriram said:
C