Search found 8 matches
This is 750+ question.
it is definitely B.
any line will cross the X-ax if the slop is not zero.
A doesn't tell us anything about the slop
B tells us ab>0 hence neither a nor b equals zero. since -a/b is the slop of this line and since a is not zero, then the slop is not zero.
answer is B
- by YTarhouni
Sun Sep 17, 2017 9:08 pm- Forum: Data Sufficiency
- Topic: GMAT Prep Ques (Equation of line)
- Replies: 5
- Views: 4818
at 3:20. Train A would have traveled 10 miles (Speed*time=30*1/3=10). the distance now is only 80 miles.
now the two trains are traveling toward each others at a combined speed of 30+10=40. the 80 miles will be traveled in a 2 hours (distance/speed=80/40=2).
3:20+2:00=5:20
- by YTarhouni
Tue Sep 05, 2017 7:12 pm- Forum: Problem Solving
- Topic: Time rate and distance
- Replies: 8
- Views: 5815
When it comes to calculating the number of item in a sequence of multiples, i find it easy to divide first term and last term by the multiple then apply the formula of (last-First+1).
In this case:
84/7=12
140/7=20
#items=20-12+1=9
from here you can follow any approach that makes you comfortable.
- by YTarhouni
Tue Sep 05, 2017 6:45 pm- Forum: Problem Solving
- Topic: multiples of 7
- Replies: 9
- Views: 11208
- by YTarhouni
Sun Sep 03, 2017 2:20 pm- Forum: Problem Solving
- Topic: Tough one from Kaplan
- Replies: 7
- Views: 4886
Math:
P(R&R)=P(B&B)=P(G&G)=2/6*1/5=2/30
Total probability=P(R&R+P(B&B)+P(G&G)=2/30+2/30+2/30=6/30=1/5
- by YTarhouni
Sun Sep 03, 2017 2:11 pm- Forum: Problem Solving
- Topic: Probability - 2 Pairs of Socks
- Replies: 14
- Views: 23184
Alternative:
P( A&B or B&A)=2*2/9*3/8=12/72
P(A&P or P&A)=2*2/9*4/8=16/72
P(B&P or P&B)=2*3/9*4/8=24/72
Total probability=12/72+16/72+24/72=52/72=13/18
- by YTarhouni
Sun Sep 03, 2017 1:39 pm- Forum: Problem Solving
- Topic: Probability Problem Sets
- Replies: 5
- Views: 4716
Use complement.
P(at least one pair)=1-P(no pairs).
P(no pair)=4C2 (possible combinations of pairs) *P(one number)*P(of not that one number)*P(not the two previous numbers)*P(not three previous numbers).
P(no pair)=6*1/6*5/6*4/6*3/6=60/216=5/18
1-5/18=13/18
- by YTarhouni
Sun Sep 03, 2017 1:24 pm- Forum: Problem Solving
- Topic: Probablity
- Replies: 16
- Views: 6823
- by YTarhouni
Fri Aug 25, 2017 5:57 pm- Forum: Problem Solving
- Topic: integer m
- Replies: 5
- Views: 4212