Search found 26 matches
Well I really appreciate all the graphical methods but the same may not be applied if the equation changes. How I did it when two lines are perpendicular to each other the product of the slopes of the two lines is -1. m1 * m2 = -1. Also slope of the bisector ( m1 ) is -2 ( y= m x + c) so slope ( m2 ...
- by smanstar
Fri Nov 02, 2012 5:14 am- Forum: Problem Solving
- Topic: Beat this: Coordinate Geometry
- Replies: 14
- Views: 4177
- by smanstar
Wed Oct 31, 2012 9:25 pm- Forum: Problem Solving
- Topic: Mitch and other Experts pls help
- Replies: 5
- Views: 1474
- by smanstar
Tue Oct 30, 2012 11:03 pm- Forum: Problem Solving
- Topic: Mitch and other Experts pls help
- Replies: 5
- Views: 1474
Mitch and other Experts pls help
Escalator is moving from first floor to ground floor in a shopping complex. Jack took 30 seconds to reach the ground floor if he takes 25 steps but if he triples his speed it takes him only 18 seconds .
a) Total steps in the stationary escalator.
b) Time taken if only the escalator was in motion
- by smanstar
Tue Oct 30, 2012 11:02 pm- Forum: Problem Solving
- Topic: Mitch and other Experts pls help
- Replies: 5
- Views: 1474
a^n + b^n is divisible by (a+b) is n is odd.
Since in this question we find 22 + 88 = 110 , thus all the terms will be divisible by 110, except for the middle term ( as 22- 88 we have odd no of numbers) which is 55^3
So remainder is (55*55*55)/ 110 which is 55 itself.
- by smanstar
Sat Oct 27, 2012 4:27 am- Forum: Problem Solving
- Topic: If 22^3+23^3+24^3+....
- Replies: 4
- Views: 2269
Circular track
two persons A & B are running in a circular track of length 1000 meters, starting at P.
speed of A is greater than speed of B.
If they meet for the second time at a point Q, 800 meters from P.
Find the first meeting point
- by smanstar
Sun Oct 21, 2012 7:54 am- Forum: Problem Solving
- Topic: Circular track
- Replies: 1
- Views: 1051
Triangles..
perimeter of triangles is 28.
If all sides are integers , find the number of such triangles possible ??
- by smanstar
Sun Oct 21, 2012 7:45 am- Forum: Problem Solving
- Topic: Triangles..
- Replies: 1
- Views: 955
Since ABC is equilateral triangle , its angles are 60
the angle subtended by the minor arc abc at centre will be twice of angle subtended at circumference
So angle at centre is 120
thus the major arc abc subtends 240 at the centre.
A/q
24 = 2(pi)R * ( 240/360)
Solving u get 2R = 11.
- by smanstar
Sun Oct 21, 2012 7:42 am- Forum: Problem Solving
- Topic: GMATPrep 1 Geometry Question
- Replies: 3
- Views: 1659
Since we have n = 16 and it is divided by 17.
We have to use Wilson's formula
As 17 is a prime number so (17-1)! + 1 is a multiple of 17.
hence 16! is 17k -1
thus remainder is -1/17 or 16
So ans is n.
- by smanstar
Sat Oct 13, 2012 9:14 am- Forum: Problem Solving
- Topic: Combinatorics
- Replies: 4
- Views: 2009
1. a+b+c = 20 no of positive integral solution if a>b>c ? 2 . a+b+c <= 20 no of positive integral solution ? Hi, there. I'm happy to share my 2¢ on this. :-) First, just to be clear, this is NOT a possible GMAT question. This involves a lot of tedious listing out of possibilities --- there's reall...
- by smanstar
Wed Sep 26, 2012 10:25 pm- Forum: Problem Solving
- Topic: no of positive integral solution
- Replies: 6
- Views: 2927
no of positive integral solution
1. a+b+c = 20
no of positive integral solution if a>b>c ?
2 . a+b+c <= 20
no of positive integral solution ?
- by smanstar
Wed Sep 26, 2012 5:50 am- Forum: Problem Solving
- Topic: no of positive integral solution
- Replies: 6
- Views: 2927
In how many ways can you distribute 30 identical balls in 7 boxes (B1, B2..., B7) Such that : No 2 boxes have same no of balls and at-least 1 ball is in each box ? 1+2+3+4+5+6+7 = 28. This represents the MINIMUM number of balls needed to satisfy the conditions that no box is empty and that each of ...
- by smanstar
Wed Sep 26, 2012 5:35 am- Forum: Problem Solving
- Topic: Gmat teaser
- Replies: 3
- Views: 1471
What I did was
P( white marble) = 1/2
P ( black marble) = 1/2
So 5 girls selecting 5 white marbles and 5 boys selecting 5 black marbles
P = 1/2 * 1/2 * ...... 10 times = 1/2^10
Can someone explain where I am going wrong ???
- by smanstar
Tue Sep 25, 2012 10:29 pm- Forum: Problem Solving
- Topic: Probability - 10 marbles
- Replies: 143
- Views: 55326
When replaced: probability of the 1st card to be red = 1/4 when we replaced, we will have the same set of cards probability for an ace = 4/52 probability of both events to happen = 1/4 * 4/52 = 1/52 when not replaced: probability of the 1st card to be red = 13/52 but the 1st card can be red ace too...
- by smanstar
Tue Sep 25, 2012 10:08 pm- Forum: Problem Solving
- Topic: probability of red and ace ???
- Replies: 4
- Views: 1689
- by smanstar
Tue Sep 25, 2012 9:26 pm- Forum: Problem Solving
- Topic: permutations and combinations
- Replies: 4
- Views: 11014