Search found 22 matches
a # b = b # a
a # 0 = a
(a # b) # c = a # (b # c)
a=1, b=2, c=3
1+2-2 = 2+1-2 +> 1=1 true
1+0-0 = 1 =>1=1 true
(1+2-2)#3 = 1 # (2+3-6) => 1#3 = 1#-1 => 1+3-3=1-1+1 => 1=1 true
- by sunilramu
Mon Jun 13, 2011 4:12 pm- Forum: Problem Solving
- Topic: a # b = a + b – ab
- Replies: 3
- Views: 4308
- by sunilramu
Mon Jun 13, 2011 12:57 pm- Forum: GMAT Math
- Topic: silly math question
- Replies: 9
- Views: 2075
N < 200
14*N / 60 is an integer.
=> 2.7.N/2.2.3.5 is an integer
=> N should at least have 2.3.5 in it.
=> Now if you add next prime factor(7) to the list. It would make n > 200 (2.3.5.7 = 210)
So N has 3 distinct positive prime factors.
- by sunilramu
Mon Jun 13, 2011 12:55 pm- Forum: Problem Solving
- Topic: Value of N!
- Replies: 3
- Views: 995
- by sunilramu
Sat Jun 11, 2011 5:01 am- Forum: Critical Reasoning
- Topic: Ernesto: Sales of VCRs—videocassette recorders—will decline
- Replies: 10
- Views: 3647
- by sunilramu
Sat Jun 11, 2011 5:00 am- Forum: Critical Reasoning
- Topic: Ernesto: Sales of VCRs—videocassette recorders—will decline
- Replies: 10
- Views: 3647
Solution approach
If there were no restrictions then we could have 6! = 720 ways
If we have Frankie in the first slot we will have 5! = 120 ways
But Frankie can be in other slots as well. So the only answer 120 < 360 < 720 should be the solution.
IMO D
- by sunilramu
Fri Jun 10, 2011 10:36 am- Forum: Problem Solving
- Topic: Combinatorics - 700+
- Replies: 8
- Views: 2233
Mitch,
Can you please elaborate on how you arrived at the premise that speeds of both A and B should to be factors of 480.
Thanks
- by sunilramu
Thu Jun 09, 2011 4:46 pm- Forum: Problem Solving
- Topic: Difficult Math Question #6
- Replies: 9
- Views: 21117
Plugging in results. Eliminate B and C since they are greater than 18. plugging in 8. 8(x) + 10 (6.7) = 87 => x = 2.5 validate if, 8(6.7) + 10(2.5) = 78.6 and answer is yes. I chose 8 because 8 * 6.7 would give me a unit digit of 6 in 78.6 and the other number would be 10 which would cancel out deci...
- by sunilramu
Wed Jun 08, 2011 7:13 am- Forum: Problem Solving
- Topic: Good Mixture sum
- Replies: 3
- Views: 3231
Say there were 60 rooms. The we can arrive at the following table using given data. --------------------------------------- | Rented | Not Rented |Total --------------------------------------- AC | 24 | 12 | 36 --------------------------------------- No AC | 21 | 3 | 24 -----------------------------...
- by sunilramu
Mon Jun 06, 2011 4:48 pm- Forum: Problem Solving
- Topic: Set problem
- Replies: 7
- Views: 1648
- by sunilramu
Mon Jun 06, 2011 12:21 pm- Forum: Data Sufficiency
- Topic: Data Sufficiency Books
- Replies: 7
- Views: 1462
- by sunilramu
Mon Jun 06, 2011 10:18 am- Forum: Problem Solving
- Topic: easy prob bt cudnt do
- Replies: 3
- Views: 966
- by sunilramu
Mon Jun 06, 2011 7:01 am- Forum: Problem Solving
- Topic: Square
- Replies: 12
- Views: 4064
3^6 - 3 = 726
E
There are only 5 blocks of each color available, hence you cannot cover the entire floor with one color. We have to subtract three patterns that have only one color.
- by sunilramu
Mon Jun 06, 2011 4:59 am- Forum: Problem Solving
- Topic: rectangular floor
- Replies: 3
- Views: 1912
1. X + Y not equal to 73 - True as X and Y should both be odd and sum should be even.
2. XY is an odd integer - True as X and Y are both odd and product should be odd
3. X/Y is not an integer - True as X and Y are different and are primes.
IMO E
- by sunilramu
Mon Jun 06, 2011 4:19 am- Forum: Problem Solving
- Topic: Prime numbers
- Replies: 10
- Views: 3858
Given that the arc inscribes 2 of the 3 equal sides of the triangle. The defined arc will form the 2/3rd of circumference the circle.
Therefore,
2/3 * Pi. D = 24
=> D = 36/Pi ~ 11
- by sunilramu
Sun Jun 05, 2011 9:17 am- Forum: Problem Solving
- Topic: diameter of circle
- Replies: 7
- Views: 1228