ETS DS questions...plz explain

[farooq]

1. While Mel is on disability leave, his employer pays him a monthly disability benefit equal to $1,200 plus 40 percent of the amount of his monthly salary in excess of $2,000. What is Mel's monthly salary?

(1) Mel's monthly disability benefit from his employer is $1,600.
(2) Mel's monthly salary exceeds $2,500.

2. If car X followed car Y across a certain bridge that is 21mile long, how many seconds did it take car X to travel across the bridge?

(1) Car X drove onto the bridge exactly 3 seconds after car Y drove onto the bridge and drove off the bridge exactly 2 seconds after car Y drove off the bridge.
(2) Car Y traveled across the bridge at a constant speed of 30 miles per hour.

3. If n is a positive integer, what is the tens digit of n?

(1) The hundreds digit of 10n is 6.
(2) The tens digit of n + 1 is 7.

4. Is | x + 2 | < 3?
(1) x < 1
(2) x > -5

https://www.urch.com/forums/attachments/ ... temp11.jpg

5. The figure above shows the number of meters in the lengths of the four sides of a jogging path. What is the total distance around the path?

(1) One of the sides of the path is 120 meters long.
(2) One of the sides of the path is twice as long as each of the two shortest sides.

[GmatVerbal]

Q3)

The hundreds digit of 10n is 6. => 10 th digit is 6 --> this is sufficient

The tens digit of n + 1 is 7. we can't say. Because if depends on what is the first digit. If its 9 => 10 digit is 6. if not it is 7.

=> 1 is sufficient.

Q4) is | x + 2 | < 3? This equation can be split in to two equations based on x value

is x+2 < 3 ? for x > -2 ---> call it (a)
is x+2 > 3 ? for > -2 -----> call it (b)


1) x < 1 => the original equation can be (a) or (b) depending on x < -2 or -2<x<1
--> not sufficient

2) x> -5 => it could be (a) or (b) depending on -5<x<-2 or x>-2

if we take both 1 &2 => -5<x<1 still depending on the value of x it could (a) or (b)

=> answer is both together also not sufficient.

[2010gmat]

1 a
2 c
3 a
4 c

[sunnyjohn]

1. While Mel is on disability leave, his employer pays him a monthly disability benefit equal to $1,200 plus 40 percent of the amount of his monthly salary in excess of $2,000. What is Mel's monthly salary?

(1) Mel's monthly disability benefit from his employer is $1,600. ==> Sufficient :- 40% is {1600-1200} ==> u can find 100%.
(2) Mel's monthly salary exceeds $2,500. ==> can have infinite values.

IMO: A

2. If car X followed car Y across a certain bridge that is 21mile long, how many seconds did it take car X to travel across the bridge?

(1) Car X drove onto the bridge exactly 3 seconds after car Y drove onto the bridge and drove off the bridge exactly 2 seconds after car Y drove off the bridge.
(2) Car Y traveled across the bridge at a constant speed of 30 miles per hour.

You need relative speed here.
A) tell that Car X travale the distance in time_of_Y - 1 seonds. ==> Y's time or speed can be anything.
B) Y speed is given ==> use A option and Question can be solved.
IMO: C

3. If n is a positive integer, what is the tens digit of n?

(1) The hundreds digit of 10n is 6.
(2) The tens digit of n + 1 is 7.

anything mulitplied by 10, have 0 as unit digit, whereas previous unit digit become tenth digit and previous tenth become hundred. So A) ==> give u the anser.
B) could 69 or could be 71
IMO:A
4. Is | x + 2 | < 3?
(1) x < 1
(2) x > -5
Solve it:
|x+2| - 3 < 0 ==> negative ?

A) if x is less than 1 ==>
X = 0 ==> 2 -3 = -1 yeah
X = -8 ==> 6-3 = 3 No
INSUFFICIENT
B) X > -5
put X = 0 ==> 2-3 = -1 Yeah
X = 8 ==> 10-3 = 7 NO

Join A and B
|x+2| will always be less than 3 if X is in between 1 and -5.
See X is not equal to 1 and 5. So IMO:C
https://www.urch.com/forums/attachments/ ... temp11.jpg

5. The figure above shows the number of meters in the lengths of the four sides of a jogging path. What is the total distance around the path?

(1) One of the sides of the path is 120 meters long.
(2) One of the sides of the path is twice as long as each of the two shortest sides.