official quant thread for cat08

[amitnsitian]

Originally Posted by nikunj14_83

Hi ,
Can any one tell me where am I going wrong in this ques....

What is the radius of circle?

Let the points be E,F where the square intersects the circle
Joining points E,F we get a quad AEFD
Diagonal of the quad shud be diameter for the square
Let AE=x;EF=10(given);ED=2R Centre=O
10^2+x^2=4R^2-----(1)
Frm trangle AOE
x^2=2R^2----(2)
Solving 1,2
we get R=10/sqrt2.... which is wrong can u plz tell me why???

Can you explain this line? It seems to be a little wrong

[man_on_mission]

Originally Posted by dashing

How ?
i am unable to understand the solution
is it some theorem ?

No dude not any theorem...just simple median funda...for ur convenience..i m attaching a better xplanation....

Hope it helps..else let me know....

[man_on_mission]

Originally Posted by nikunj14_83

Hi ,
Can any one tell me where am I going wrong in this ques....


What is the radius of circle?

Let the points be E,F where the square intersects the circle
Joining points E,F we get a quad AEFD
Diagonal of the quad shud be diameter for the square
Let AE=x;EF=10(given);ED=2R Centre=O
10^2+x^2=4R^2-----(1)
Frm trangle AOE
x^2=2R^2----(2)
Solving 1,2
we get R=10/sqrt2.... which is wrong can u plz tell me why???

i guess for the bold text u mean tat diameter of circle will be diagonal of AEFD....den i think ur method is correct...

i guess der is some calculation mistake...
by ur method answer will b radius = 5sqroot2

[getintoiimb]

guys just a query..sorry for spamming..
i am currently doing arun sharma for quants..the problems which i post on this thread are mostly LOD(level of difficulty) 2 probs..is it necessary to do LOD 3 from arun sharma?i find them way too tough and too much to time consumption(not asked in CAT)..i do only the LOD 1 and LOD 2 problems..guys whove done and who are doing arun sharma..pls suggest!

[asghan]

Originally Posted by getintoiimb

guys just a query..soory for spamming..
i am currently doing arun sharma for quants..the problmes which is post on this thread are mostly LOD 2 probs..is it necessary to do LOD 3 from arun sharma?i find them way too tough(not asked in CAT)..i do only the LOD 1 and LOD 2 problems..guys whove done and who are doing arun sharma..pls help!

Even I am doing quant by arun sharma, I guess we should try to do some problems from lod-3 also as few prob are good, though i can't say much about it as i have only finished no. system and doing lod-2 for progressions

[man_on_mission]

Originally Posted by getintoiimb

guys just a query..sorry for spamming..
i am currently doing arun sharma for quants..the problems which i post on this thread are mostly LOD(level of difficulty) 2 probs..is it necessary to do LOD 3 from arun sharma?i find them way too tough and too much to time consumption(not asked in CAT)..i do only the LOD 1 and LOD 2 problems..guys whove done and who are doing arun sharma..pls suggest!

I also found LOD3 probs very tuf..nd generally probs of tat difficulty level r not asked in CAT..but des probs gives ur brain a good excercise....wen u toil hard nd come out wid the correct answer it gives u a lot of satisfaction and confidence...wat i did..i didnt solve all the LOD3 probs but i selected few probs nd solved em...u may also try few LOD3 probs..

[naga25french]

Originally Posted by gautamgomzi

Plz help. Concept nt clear...

1.) Find the maximum value of n such that 157! is perfectly divisible by 18^n. Ans- 37

2.) Find the max. value of n such that 50! is perfectly divisible by 12600^n. Ans- 6

3.) Find the max. value of n such that 77! is perfectly divisible by 720^n. (For this one my answer is coming 17 bt tha answer is 17 as stated)Plz try 2 explain the solution if possible...thnx...GK

1)18 = 2 * 3^2

so we can easily say 3 is the deciding factor
so count the number of 3 in 157!


so answer is

157/3=52
52/3 = 17
17/3 = 5
5/3=1

total = 52+17+5 + 1 = 75

so answer is 75/2 = 37...


2)12600 = 7 * 5^2* 2^3 * 3^2


clearly we can say 7 or 5 is the deciding factor

so count the number of 5 and 7 in 50!
50/5=10
10/5 = 2

so total is 12 answer is 12 /2 = 6

50/7 = 7 ... answer is 7

6 < 7
so we get answer as 6


3) 720 = 6!

the highest prime number with in 6 = 5

so count number of 5 in 77!

77/5 = 15

15/5 = 3

so answer according to me is 18..


hope the solution is clear

[nikunj14_83]

Originally Posted by man_on_mission

i guess for the bold text u mean tat diameter of circle will be diagonal of AEFD....den i think ur method is correct...

i guess der is some calculation mistake...
by ur method answer will b radius = 5sqroot2

Hi,
If u see the quad AEFD it is a rectangle & acc to the theorm ..if a rectangle is inscribed in a circle the diagonal of the rectangle forms the diameter of the circle....but i am getting ans as 10/sqrt2=5 sqrt2 as u mentioned but it is wrong so can u find the radius by ur method....Ans is 6.25

[Flameboy007]

Originally Posted by nikunj14_83

Hi,
If u see the quad AEFD it is a rectangle & acc to the theorm ..if a rectangle is inscribed in a circle the diagonal of the rectangle forms the diameter of the circle....but i am getting ans as 10/sqrt2=5 sqrt2 as u mentioned but it is wrong so can u find the radius by ur method....Ans is 6.25

Dude, don think that the theorem is applicable in this prob, since the rectangle is not inscribed in the circle. Or I did not understand you.

Anyway, attaching the solution

[kewl.bantee]

[quote=naga25french;1094582]1)18 = 2 * 3^2

so we can easily say 3 is the deciding factor
so count the number of 3 in 157!


so answer is

157/3=52
52/3 = 17
17/3 = 5
5/3=1

total = 52+17+5 + 1 = 75

so answer is 75/2 = 37...


2)12600 = 7 * 5^2* 2^3 * 3^2


clearly we can say 7 or 5 is the deciding factor

so count the number of 5 and 7 in 50!
50/5=10
10/5 = 2

so total is 12 answer is 12 /2 = 6

50/7 = 7 ... answer is 7

6 < 7
so we get answer as 6


3) 720 = 6!

the highest prime number with in 6 = 5

so count number of 5 in 77!

77/5 = 15

15/5 = 3

so answer according to me is 18..


hi
u solved it thru any concepts or just with a short cut method.in the 2nd ques u didnt divide 7 by 2.and why r we dividing 2 in the last step.can u plz explain it? and why cant we solve ques 3 based on the initial method tht was applied in 1 and 2.