PG Premier League - Chennai Dream Team

[ramaan]

Originally Posted by satanica

Some more problems to be worked upon (a tad simpler and with options but then anything is good for practice).

P1
How many 2-digit numbers are there such that the sum of the digits
plus the product of the digits equals the number itself?
(A) 2 (B) 9 (C) 10 (D) 18 (E) None of the above

for this,a+b+ab=10a+b
ab=9a
so,b=9..then a can be 1 to 9..the numbers are 19,29,39..99..
so answer is b)9

[nishant_rungta]

Originally Posted by satanica

Some more problems to be worked upon (a tad simpler and with options but then anything is good for practice).

P1
How many 2-digit numbers are there such that the sum of the digits
plus the product of the digits equals the number itself?
(A) 2 (B) 9 (C) 10 (D) 18 (E) None of the above


P4
What is the area of a 13-14-15 triangle?
(A) 80 (B) 82 (C) 84 (D) 86 (E) 88

P1: x+y+xy = 10x + y

Hence from the above equation y=9

Hence the numbers are 19, 29, 39, 49, ... 99. In total 9 numbers.

P2: Hero's formula : Answer 84

Solved just these two so far. Would solve others in sometime

Satan.. in Problem 6 do we consider that the amount of rope used to tie the ropes together is negligible??

And thanks a ton for ur esteemed presence on this thread. Surely makes it the most happening thread in DT segment

Can we have problems on one particular topic everyday?? Why not do this?? PnC would make a perfect start. Please please please please please lets have this...


Nishant

[ramaan]

[quote=satanica;1216948]Some more problems to be worked upon (a tad simpler and with options but then anything is good for practice).

P5
Five percent of a group of people are drug-users. Everyone in the group is administered a drug test which is known to be 90% accurate (i.e., 90% of
users taking the test are shown to be users, and 90% of nonusers taking the test are shown to be nonusers). If the test indicates that a random person in the group is a user, (approximately) what is the probability that this is a "false positive," i.e., that this result is inaccurate?
(A) 10% (B) 32% (C) 50% (D) 68% (E) 90%

Ans : (A) 10 %

Take example of 200 people...10 are drug users..190 non-users..

But in test it will show 9 are drug users..171 non-users..so test is giving wronng infromation for 1+19 users out of 200 users...

20 out of 200=10%...

[ramaan]

[quote=satanica;1216948]Some more problems to be worked upon (a tad simpler and with options but then anything is good for practice).

P2
What is length of the side of the largest square with one vertex at the
origin that will fit inside the parabola y = x^2?
(A) 1 (B) p2 (C) 2 (D) p3 (E) 3

Satan...whats the option B and D indicates.....

[maverick_srikan]

P3
Consider the real solutions of the equation
x^4 − 10*(x^2) + 1 = 0 .
What is the product of all their cubes?
(A) −10 (B) −1 (C) 1 (D) 10 (E) 10sqrt(6)

x^4-10*x^2+25-24=0

(X^2-5)^2=24

x^2-5= +/- 2(root)6

x^2= 5+/-2(root)6 or x= +/-(root3 +/- root2)

Satan, How do I get the product of the cubes now?

[krsh.vik]

P3
Consider the real solutions of the equation
x^4 − 10*(x^2) + 1 = 0 .
What is the product of all their cubes?
(A) −10 (B) −1 (C) 1 (D) 10 (E) 10sqrt(6)

answer is c

all we need to check whether all the roots are real or not

nice question satan

[murty001]

To all those who think they have done badly in 0909, I have a net score of 14 with 13 in DI. Yes it's that bad. Felt like getting drunk big time yesterday, but then I thought that having a bad mock and getting kicked from the house the same day, doesn't sound too good.

No, I didn't sleep through the mock, I was not having fever and no, I did not drink and go for the exam. I just felt incapable of cracking that paper. If on 16th November I see a paper like this, I wouldn't waste 2.5 hours sitting there. I will just hand over the paper and walk out and never attempt CAT again (which I will not do after this season anyway).

I don't have promises like 'I will crack the next mock' etc etc. I don't even know what to do at this point of time. And I don't even know if I should be taking the next mock. Maybe I need a break, maybe not.

And captain, I am not sure if I will be contributing majorly on this thread for the next few weeks. If needed, you can as well find a replacement to fill up the place in the team. I just need some time to come out of this mess.

Cheers..

[satanica]

Originally Posted by nishant_rungta

...

Satan.. in Problem 6 do we consider that the amount of rope used to tie the ropes together is negligible??

And thanks a ton for ur esteemed presence on this thread. Surely makes it the most happening thread in DT segment

Can we have problems on one particular topic everyday?? Why not do this?? PnC would make a perfect start. Please please please please please lets have this...


Nishant

Well, for P6 consider it negligible.
If you want, I can give you the thickness of rope, its density, the length used up in knots and the force applied by the 'poor' cow.

It's just not me alone who makes this thread a happening place. Rather it's everyone who solves a question and then tries to debate over it. Afterall discussions always lead to the correct and best ways to finding solutions.
Topic-wise questions, umm... well.. let's see. I do not have a repository of topicwise questions with me but lemme try to come up with some questions.

Can we have inferential RCs with proper keys and some explanations for answers? Maybe some difficult passages picked up from mocks of previous years.

Originally Posted by ramaan

Some more problems to be worked upon (a tad simpler and with options but then anything is good for practice).

P2
What is length of the side of the largest square with one vertex at the
origin that will fit inside the parabola y = x^2?
(A) 1 (B) p2 (C) 2 (D) p3 (E) 3

Satan...whats the option B and D indicates.....

A slip in editing. I have made corrections in original post too.
(B) is sqrt(2).
(D) is sqrt(3).

[exile]

Originally Posted by satanica

Some more problems to be worked upon (a tad simpler and with options but then anything is good for practice).

P1
How many 2-digit numbers are there such that the sum of the digits
plus the product of the digits equals the number itself?
(A) 2 (B) 9 (C) 10 (D) 18 (E) None of the above

10a + b = a+b+ab
9a =ab
b=9

a can take nine values, 1-9
Ans b.

Originally Posted by satanica

P7
A student is treated to a four-course meal, presented in random order. If the student eats a course and it is the best course he has eaten at that meal, he exclaims "Wow!" (For example, he will necessarily express delight after the first course.) What is the expected number of times that the student exclaims "wow"?
Assume that no two courses are equally good.
(A) 2 (B) 2.5 (C) 3 (D) 3.5 (E) None of the above

I don't get the question. What does "expected number of times" mean here?
He can exclaim "wow" maximum of four times, and minimum of one time.

[ramaan]

Originally Posted by krsh.vik

P3
Consider the real solutions of the equation
x^4 − 10*(x^2) + 1 = 0 .
What is the product of all their cubes?
(A) −10 (B) −1 (C) 1 (D) 10 (E) 10sqrt(6)

answer is c

all we need to check whether all the roots are real or not

nice question satan

Can u explain this in detail..didn't understand this...