Search found 33 matches


Basic Probablity Questions

1.Ticket numbered from 1 to 20 are mixed up and then a ticket is drawn at a random . What is the probablity that the ticket drawn has a number which is multiple of 3 or 5? 1/2,3/20,2/5,1/2 for this do we have to consider 15 also as it is divisible by 3 and 5 both ? 2.In a box there are 8 red , 7 blu...

by sixpointer

Sat Nov 13, 2010 11:14 am
Forum: Problem Solving
Topic: Basic Probablity Questions
Replies: 1
Views: 1151

Thankyou seniors :)

by sixpointer

Thu Nov 04, 2010 9:54 pm
Forum: Problem Solving
Topic: Allegation
Replies: 16
Views: 25931

I'm not sure about Alligation Method. But I think it should be in this way: The original mixture 125 Gallons at 20% water ( A ) Added water Y Gallons at 100% water. (B) New mixture X Gallons at 25% water ( The Result) Each gallon of pure water added is surplus of 75% water compared to the desired r...

by sixpointer

Thu Nov 04, 2010 11:44 am
Forum: Problem Solving
Topic: Allegation
Replies: 16
Views: 25931

Hi, Because we'll add more water into the original mixture, then the no. of gallons of wine is unchanged. In the original 125 gallons of mixture, 20% is water, thus 80% is wine. Hence, no. of gallons of wine: 125 * 80% = 100 gallons In the new mixture, water makes up 25%, thus 75% is wine. As no. o...

by sixpointer

Thu Nov 04, 2010 10:40 am
Forum: Problem Solving
Topic: Allegation
Replies: 16
Views: 25931

Allegation

A mixture of 125 gallons of wine and water contains 20% water .How much water must be added to the mixture in order to increase the percentage of water to 25% of the new mixture ?????
a 10 gals
b 8.5 gals
c 8 gals
d 6.66 gals
e 8.33 gals

Please use allegation approach

by sixpointer

Thu Nov 04, 2010 10:08 am
Forum: Problem Solving
Topic: Allegation
Replies: 16
Views: 25931

one more :- A, B, C and D are four towns any three of which are non-collinear. Then the number of ways to construct
three roads each joining a pair of towns so that the roads do not form a triangle is

9 , 10 , 12 , 24

by sixpointer

Wed Oct 27, 2010 12:07 pm
Forum: Problem Solving
Topic: Tricky PnC and probablity question
Replies: 11
Views: 5136

If x is a positive integer, what is the remainder when [ 7^(12x+3) ] + 3 is divided by 5? (A) 0 (B) 1 (C) 2 (D) 3 (E) 4 [spoiler]OA (B)[/spoiler] 7^(12x+3) % 5 = 7^12x*7^3 % 5 => 2^12x*2^3 % 7 Now 4%5 = -1(remainder) So, 2^4 will give remainder as 1 with 5 Take any value of x u will always get 1 as...

by sixpointer

Wed Oct 27, 2010 11:16 am
Forum: Problem Solving
Topic: Divisibility/ Number Props
Replies: 6
Views: 1573

@Shovan bhai can you please explain me probablity question ? If your answer is incorrect then I believe you have to subtract 6 instead of 3. (347,357,367, And 763,753,743) calculated twice. Once from 3 to 10 and other from 7 to 3. Question is asking minimum is 3 or maximum is 7 So in these 6 cases ...

by sixpointer

Wed Oct 27, 2010 11:03 am
Forum: Problem Solving
Topic: Tricky PnC and probablity question
Replies: 11
Views: 5136

Hej guys, 14. A famer has 10 sheep 4 black and 6 white. He would like to take 3 of the sheep to get shaved. How many different groups of 3 sheep can he select that would have at least one black one? 15. There are 10 books on a book shelf, 5 Math, 3 History and 2 Art. If 2 books are selected at rand...

by sixpointer

Wed Oct 27, 2010 10:59 am
Forum: Problem Solving
Topic: Combinations
Replies: 5
Views: 1690

@Shovan bhai can you please explain me probablity question ? If your answer is incorrect then I believe you have to subtract 6 instead of 3. (347,357,367, And 763,753,743) calculated twice. Once from 3 to 10 and other from 7 to 3. Question is asking minimum is 3 or maximum is 7 So in these 6 cases ...

by sixpointer

Wed Oct 27, 2010 10:51 am
Forum: Problem Solving
Topic: Tricky PnC and probablity question
Replies: 11
Views: 5136

can u explain the sign DSTU ?

by sixpointer

Wed Oct 27, 2010 10:36 am
Forum: Problem Solving
Topic: Parallelogram
Replies: 9
Views: 1581

@Shovan bhai can you please explain me probablity question ?

by sixpointer

Wed Oct 27, 2010 10:29 am
Forum: Problem Solving
Topic: Tricky PnC and probablity question
Replies: 11
Views: 5136

reddy43 wrote:for n things not to be in their right places
no. of ways = n!{1/2!-1/3!+....(-1)^n*1/n!} where n>=2
so we will have this one as 265 ways

can u explain me how does this formula work ? what is the logic behind this? where to use :)

by sixpointer

Wed Oct 27, 2010 7:41 am
Forum: Problem Solving
Topic: Tricky PnC and probablity question
Replies: 11
Views: 5136

My solution: 1. 1 - P(only one remain after 10 years) - p(no one remains after 10 years) P(no one remains after 10 years) = 0.8*0.7*0.6*0.5*0.4*0.3*0.2*0.1 P(1 remains after 10 years) = 0.2*0.7*0.6*0.5*0.4*0.3*0.2*0.1 + 0.8*0.3*0.6*0.5*0.4*0.3*0.2*0.1 + 0.8*0.7*0.4*0.5*0.4*0.3*0.2*0.1 + 0.8*0.7*0.6...

by sixpointer

Wed Oct 27, 2010 7:01 am
Forum: Problem Solving
Topic: Tricky PnC and probablity question
Replies: 11
Views: 5136

work n Time

A tank of capacity 25 liters has an inlet and an outlet tap. If both a opened simultaneity, the tank is filled in 5 minutes. But if the outlet flow rate is doubled and taps opened, the tank never gets filled up. Which of hte following can be the outlet flow rate in liters per minute. 2 6 4 3 1 I Tie...

by sixpointer

Wed Oct 27, 2010 6:57 am
Forum: Problem Solving
Topic: work n Time
Replies: 1
Views: 6967