GMAT Problem Solving Discussions

[mucool]

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.

First of all...thanx to prav for a real DS problem...gud!! I wud suggest all of you to try this...this is the toughie level!!

Soln:

without looking at the statements try to solve the problem....
by simple speed distance time equations...you would get a quadratic equation...
Solving you wud get d = 150 miles or 133.33 miles.
that is two probable answers....for these two values you will get two times....

when d =150, Train A 4:30 and train B 4:20
or you could have
when d=133.33 miles, train A 4:20 and train B 4:30....since it is a quadratic expression...

now this is where DS comes in...till here it was a PS.

from statement 1...you could pick one answer....150 miles...and time Train B arrive in New York is 4:20

from statement 2....simply trainB arrives at 4:20

So answer is D....either suffices.

cheers!!

wot say pravs??

[nairpraveenk]

Originally Posted by mucool

First of all...thanx to prav for a real DS problem...gud!! I wud suggest all of you to try this...this is the toughie level!!

Soln:

without looking at the statements try to solve the problem....
by simple speed distance time equations...you would get a quadratic equation...
Solving you wud get d = 150 miles or 133.33 miles.
that is two probable answers....for these two values you will get two times....

when d =150, Train A 4:30 and train B 4:20
or you could have
when d=133.33 miles, train A 4:20 and train B 4:30....since it is a quadratic expression...

now this is where DS comes in...till here it was a PS.

from statement 1...you could pick one answer....150 miles...and time Train B arrive in New York is 4:20

from statement 2....simply trainB arrives at 4:20

So answer is D....either suffices.

cheers!!

wot say pravs??

Perfect analysis

Hey Mukul, why dont u also post some questions, as you will be having a broader idea of what kinda Questions come ?

[nairpraveenk]

Heres is a simple problem for today.....

A Trussian's weight, in keils, can be calculated by taking the square root of his age in years. A Trussian teenager now weighs three keils less than he will seventeen years after he is twice as old as he is now. How old is he now?

(A) 14
(B) 15
(C) 16
(D) 17
(E) 18

[nairpraveenk]

Here is one more......

In a 4 person race, medals are awarded to the fastest 3 runners. The first-place runner receives a gold medal, the second-place runner receives a silver medal, and the third-place runner receives a bronze medal. In the event of a tie, the tied runners receive the same color medal. (For example, if there is a two-way tie for first-place, the top two runners receive gold medals, the next-fastest runner receives a silver medal, and no bronze medal is awarded). Assuming that exactly three medals are awarded, and that the three medal winners stand together with their medals to form a victory circle, how many different victory circles are possible?

A) 24
B) 52
C) 96
D) 144
E) 648

[mucool]

Originally Posted by nairpraveenk

Heres is a simple problem for today.....

A Trussian's weight, in keils, can be calculated by taking the square root of his age in years. A Trussian teenager now weighs three keils less than he will seventeen years after he is twice as old as he is now. How old is he now?

(A) 14
(B) 15
(C) 16
(D) 17
(E) 18

Simple one... (x^1/2) + 3 = (2x+17)^1/2
x= 4,16

answer C

[the_manager]

guys here is a SC question that i encountered with, while practicing...

Carbon-14 dating reveals that the megalithic monuments in Brittany are nearly 2,000 years as old as any of
their supposed Mediterranean predecessors.
(A) as old as any of their supposed
(B) older than any of their supposed
(C) as old as their supposed
(D) older than any of their supposedly
(E) as old as their supposedly

[the_manager]

(2x+17)^0.5 - (x)^0.5 = 3

ANS=16

[nairpraveenk]

Originally Posted by the_manager

guys here is a SC question that i encountered with, while practicing...

Carbon-14 dating reveals that the megalithic monuments in Brittany are nearly 2,000 years as old as any of
their supposed Mediterranean predecessors.
(A) as old as any of their supposed
(B) older than any of their supposed
(C) as old as their supposed
(D) older than any of their supposedly
(E) as old as their supposedly

B is the correct answer!!

Analysis:
A/C/E is not correct. The comparison is wrong.
Now this leaves us with B and D. The comparison 'older than...' is correctly used. But B has used the word 'supposed' which is correct. 'Supposedly' sounds wrong too.

[nairpraveenk]

Guys, thell me the answer for this.... also post the analysis please.....

Manufacturers sometimes discount the price of a product to retailers for a promotion period when the product is advertised to consumers. Such promotion often result in a dramatic increase in amount of product sold by the manufacturers to retailers. Nevertheless, the manufacturers could often make more profit by not holding the promotions.

Which of the following, if true, most strongly supports the claim above about the manufacturers’ profit?

(A) The amount of discount generally offered by manufacturers to retailers is carefully calculated to represent the minimum needed to draw consumers’ attention to the product.

(B) For many consumer products the period of advertising discounted prices to consumers is about a week, not sufficiently long for consumers to become used to the sale price.

(C) For products that are not newly introduced, the purpose of such promotions is to keep the products in the minds of consumers and to attract consumers who are currently using competing products.

(D) During such a promotion retailers tend to accumulate in their warehouses inventory bought at discount; they then sell much of it later at their regular price.

(E) If a manufacturer fails to offer such promotions but its competitor offers them, that competitor will tend to attract consumers away from the manufacturer’s product.

[sledgehammer]

Hi,
This is a question from scoretop SC 1000. The answer in the answer key is D, but i seriously feel it should be C.

Please help

858.There is substantial evidence that certain forms of solar energy either now or
within a few years will be economically competitive with conventional sources of
heat and power.
(A) either now or within a few years will be economically competitive with
conventional sources of heat and power
(B) will either be economically competitive with conventional sources of heat and
power within a few years or are so now
(C) will be economically competitive with conventional sources of heat and
power either now or within a few years
(D) either are now economically competitive with conventional sources of heat
and power or will be so within a few years
(E) are either now or will be within a few years economically competitive with
conventional sources of heat and power