w,x,y,z are integers such that w>x>y>z>0, is y a common devisor of w, x??
1) w/x = z^-1 + X^-1
2) w^2-wu-2w = 0.?
p,q,r.s are +ve integers, if p/q = r/s, is r devisible by 5?
1) p is a multiple of 140
2) Q = 7^x
Hi,
can anyone post the approach for the attached question. The question is from GMAT prep.
Thanks
Hi,
can anyone post the approach for the attached question. The question is from GMAT prep.
Thanks
Hi,
can anyone post the approach for the attached question. The question is from GMAT prep.
Thanks
IMO D.
the only number between 7 and 14 is 12 that is option D.
w,x,y,z are integers such that w>x>y>z>0, is y a common divisor of w, x??
1) w/x = z^-1 + X^-1
2) w^2-wu-2w = 0.?
sorry, couldn't locate the original post therefore picking from here.
I think the ans should be A. waiting for the OA before I post explanation.
Quote:
Originally Posted by nairpraveenk
Fundoo problem
-------------------
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM and if the combined travel time of the two trains is 2 hours, what time did Train B arrive in New York?
(1) Train B arrived in New York before Train A arrived in Boston.
(2) The distance between New York and Boston is greater than 140 miles.
(A) Statement (1) alone is sufficient, but statement (2) alone is not sufficient.
(B) Statement (2) alone is sufficient, but statement (1) alone is not sufficient.
(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(D) Each statement ALONE is sufficient.
(E) Statements (1) and (2) TOGETHER are NOT sufficient.
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM and if the combined travel time of the two trains is 2 hours, what time did Train B arrive in New York?
(1) Train B arrived in New York before Train A arrived in Boston.
(2) The distance between New York and Boston is greater than 140 miles.
(A) Statement (1) alone is sufficient, but statement (2) alone is not sufficient.
(B) Statement (2) alone is sufficient, but statement (1) alone is not sufficient.
(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(D) Each statement ALONE is sufficient.
(E) Statements (1) and (2) TOGETHER are NOT sufficient.
I Think Its
E Statements (1) and (2) TOGETHER are NOT sufficient.
Please Correct me If I Am Wrong.
Lets Decode It....
(1). We Only Know That Train B Arrived In Newyork Before Trian A Which Means Train B Has A Greater Constant Speed Than Train A Since Train A, After 1 Hr Of Its Departure At 4pm Passes Train B (Lets Say to An Imaginary Point C) while Train B Left Boston At 3:50 and Passes Train A At Point C after 10 Minutes.... The Combined time of both trains is 2 hrs.But Whats The Speed Of Train B ???? Since We Don't Know The Speed , We Cannot Tell The Time Of Train B .
(2) greater than 140 miles , could be 150 .......Train A Covers 100 miles in 1 hour out of the combined 2 hrs but because we don't know the speed of train B we cannot tell anything about its time. train B could have gone 120mph , 105 miles .... so not enough either....
Both Statements are still not suffiicient because we need to know the speed of train B ....
Can anyone please tell me the answer......
According to me it shd be B
Sorry for late reply. Havnt visited PS forum for last 2 days. Gosh.. how can I do that!!! 
Trains meet an hour after A left. SO When they meet, A would have travelled a distance of 100 miles.
At the same time, train B(having left at 3.50 pm) would have travelled for 10 mins. Lets say speed of B is B.
In 1/6 hours B would have travelled B/6 miles
After they meet, train A travels B/6 miles and B travels 100 miles. ---- I
Therefore, total travel time can equated as
1 + (B/6)/100 + 1/6 + (100/B) = 2
This gives B = 300 and 200
if B =200, it will take 1/2 hours cover 100 miles and reach NY. And from I we know A has to travel B/6 miles which is 200/6 miles.
A will take 1/3 hours. This way A will reach sooner than B.
if B =300, it will take 1/3 hours cover 100 miles and reach NY. And from I we know A has to travel B/6 miles which is 300/6 miles.
A will take 1/2 hours. This way B will reach sooner than A.
Now we need extra info to determine which speed of B is correct.
Options (1) Says B reaches first which totally aligns with B's speed = 300 Therefore 1 is sufficient.
Options (2) lead us anywhere. Insufficient
I hope this explanation is clear enough. But i dont know the OA yet 
Problem Stem:
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it
passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM
and if the combined travel time of the two trains is 2 hours, what time did Train B arrive in New York?
(1) Train B arrived in New York before Train A arrived in Boston.
(2) The distance between New York and Boston is greater than 140 miles.
@Bizzarenym...
could you explain how you got A?? (for the DS question about 2 trains!! )
Thanks in advance.. :)
w,x,y,z are integers such that w>x>y>z>0, is y a common devisor of w, x??
1) w/x = z^-1 + X^-1
2) w^2-wu-2w = 0.?
p,q,r.s are +ve integers, if p/q = r/s, is r devisible by 5?
1) p is a multiple of 140
2) Q = 7^x
I dont get the highlighted part in red. Can someone elaborate plz. Thanks!
Explanation for option 1.
Solving the equation => w=1+(x/z)
since w is an integer, x/z should also be an integer.
Say x=n*z where n is integer > 0
Thus, w=(1+n).
Note that y can be a common factor of w and x only in case y=1 (not possible as y>z>0) or 1+n=z (not possible as w>z).
Thus, there is no scenario where y is a common divisor of w, x
So this is SUFFICIENT.
Explanation for option 2.
Solving the equation => w(w-y-2)=0.
w cannot be 0 => w=y+2
This implies that w,x,y are consecutive integers > 1 (minimum value of z can be 1).
Note that y can be a common factor of 2 consecutive integers w and x only in case y=1 (not possible as y>z>0)
Thus, there is no scenario where y is a common divisor of w, x
So this is SUFFICIENT.
The answer is either of these statements. (Option D)
Cheers!
I Think Its
E Statements (1) and (2) TOGETHER are NOT sufficient.
Please Correct me If I Am Wrong.
Lets Decode It....
(1). We Only Know That Train B Arrived In Newyork Before Trian A Which Means Train B Has A Greater Constant Speed Than Train A Since Train A, After 1 Hr Of Its Departure At 4pm Passes Train B (Lets Say to An Imaginary Point C) while Train B Left Boston At 3:50 and Passes Train A At Point C after 10 Minutes.... The Combined time of both trains is 2 hrs.But Whats The Speed Of Train B ???? Since We Don't Know The Speed , We Cannot Tell The Time Of Train B .
(2) greater than 140 miles , could be 150 .......Train A Covers 100 miles in 1 hour out of the combined 2 hrs but because we don't know the speed of train B we cannot tell anything about its time. train B could have gone 120mph , 105 miles .... so not enough either....
Both Statements are still not suffiicient because we need to know the speed of train B ....
Iam not sure what's the answer could be.....
since the total time is 2 hrs, we can form an equation 2=D/100 + D/S where D is the total distance and S is the speed of the second train...
Another equation could be 1=100/(100+S) where (100+S) is the relative speed when both trains meet and 1 is the time in hrs, 100 miles is the distance
Solving both we get a quad. equation for D (distance) we can get 2 values; but these values are not in real no.s......
I also thnk it shd b E
Sorry for late reply. Havnt visited PS forum for last 2 days. Gosh.. how can I do that!!!
Trains meet an hour after A left. SO When they meet, A would have travelled a distance of 100 miles.
At the same time, train B(having left at 3.50 pm) would have travelled for 10 mins. Lets say speed of B is B.
In 1/6 hours B would have travelled B/6 miles
After they meet, train A travels B/6 miles and B travels 100 miles. ---- I
Therefore, total travel time can equated as
1 + (B/6)/100 + 1/6 + (100/B) = 2
This gives B = 300 and 200
if B =200, it will take 1/2 hours cover 100 miles and reach NY. And from I we know A has to travel B/6 miles which is 200/6 miles.
A will take 1/3 hours. This way A will reach sooner than B.
if B =300, it will take 1/3 hours cover 100 miles and reach NY. And from I we know A has to travel B/6 miles which is 300/6 miles.
A will take 1/2 hours. This way B will reach sooner than A.
Now we need extra info to determine which speed of B is correct.
Options (1) Says B reaches first which totally aligns with B's speed = 300 Therefore 1 is sufficient.
Options (2) lead us anywhere. Insufficient
I hope this explanation is clear enough. But i dont know the OA yet
Problem Stem:
Train A leaves New York for Boston at 3 PM and travels at the constant speed of 100 mph. An hour later, it
passes Train B, which is making the trip from Boston to New York at a constant speed. If Train B left Boston at 3:50 PM
and if the combined travel time of the two trains is 2 hours, what time did Train B arrive in New York?
(1) Train B arrived in New York before Train A arrived in Boston.
(2) The distance between New York and Boston is greater than 140 miles.
BizzareNym SaysI dont get the highlighted part in red. Can someone elaborate plz. Thanks!
oooopss..... Lazy me.. ;)
First of all... I was totally confused and could not tackle the problem. Out of my mind today... Saw the solution... and whoa
You came till the doorstep and have given up...
Now - 2 options for speed of B - 300/200
For B = 300, the distance between the cities is 150, for B = 200 the distance between the cities is 133.33.
Statement A) If B reaches NY first, we know B = 300, and hence also the time when it will reach NY.
Statement B) If the distance is greater than 140, we know that again B = 300 (If it has been less than 140, then B = 200). In either case, we can again compute the time...
So either of the statement is enough to determine when Train B reaches NY.
First of all... I was totally confused and could not tackle the problem. Out of my mind today... Saw the solution... and whoa
You came till the doorstep and have given up...
Now - 2 options for speed of B - 300/200
For B = 300, the distance between the cities is 150, for B = 200 the distance between the cities is 133.33.
Statement A) If B reaches NY first, we know B = 300, and hence also the time when it will reach NY.
Statement B) If the distance is greater than 140, we know that again B = 300 (If it has been less than 140, then B = 200). In either case, we can again compute the time...
So either of the statement is enough to determine when Train B reaches NY.
First of all... I was totally confused and could not tackle the problem. Out of my mind today... Saw the solution... and whoa
You came till the doorstep and have given up...
Now - 2 options for speed of B - 300/200
For B = 300, the distance between the cities is 150, for B = 200 the distance between the cities is 133.33.
Statement A) If B reaches NY first, we know B = 300, and hence also the time when it will reach NY.
Statement B) If the distance is greater than 140, we know that again B = 300 (If it has been less than 140, then B = 200). In either case, we can again compute the time...
So either of the statement is enough to determine when Train B reaches NY.
Can anyone please tell me the answer......
According to me it shd be B
First of all... I was totally confused and could not tackle the problem. Out of my mind today... Saw the solution... and whoa
You came till the doorstep and have given up...
Now - 2 options for speed of B - 300/200
For B = 300, the distance between the cities is 150, for B = 200 the distance between the cities is 133.33.
Statement A) If B reaches NY first, we know B = 300, and hence also the time when it will reach NY.
Statement B) If the distance is greater than 140, we know that again B = 300 (If it has been less than 140, then B = 200). In either case, we can again compute the time...
So either of the statement is enough to determine when Train B reaches NY.