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NUMBER PROPERTIES/INEQUALITY DS

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NUMBER PROPERTIES/INEQUALITY DS

by cramya » Sat Nov 15, 2008 2:53 pm
If 500 is the multiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y, which multiple of 100 is closest to x+y?

1) x<500
2) y<400


[spoiler]OA:E[/spoiler]

The hint to this problem is in the subject... :-) Found this and wanted to share it with the group...
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Re: NUMBER PROPERTIES/INEQUALITY DS

by iamcste » Sat Nov 15, 2008 3:03 pm
cramya wrote:If 500 is the multiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y, which multiple of 100 is closest to x+y?

1) x<500
2) y<400


[spoiler]OA:E[/spoiler]

The hint to this problem is in the subject... :-) Found this and wanted to share it with the group...
"500 is a multiple of 100 that is closest to x" .
-> if x were 440, the closest multiple of 100 would have been 400
-> if x were 560, the closest multiple of 100 would have been 600

So, the correct range of x values as per the qn stem is 450 < x < 550

Stem
450 < x < 550
350 < y < 450

(1) 450 < x < 500 Not sufficient
(2) 350 < y < 400 Not sufficient

Add 1 and 2
800 < x+y < 900

If x+y is 830, the closest multiple of 100 would be 800
Else if x+y is 870, the closest multiple of 100 would be 900

So, INSUFF, hence E
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by cramya » Sat Nov 15, 2008 3:09 pm
Iamcaste thats exactly the right approach to this question...

Given

451<=x<=549 (1)

351<=y<=449 (2)

Stmt I

451<=x<=499 (3)
Add 2) and 3) since the inequalities are facing in the same direction

802<=x+y<=948

Dont know if ts 800 or 900

INSUFF

Stmt II

351<=y<=399 (4)

Add 1) and 4) since the inequalities are facing in the same direction

802 <= x+y <= 948

Dont know if ts 800 or 900

INSUFF

Stmt I and II toegther tell us the same thing (same range)

802 <= x+y <= 948

Dont know if ts 800 or 900

INSUFF

E)
Last edited by cramya on Sat Nov 15, 2008 3:22 pm, edited 1 time in total.
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by logitech » Sat Nov 15, 2008 3:18 pm
Good example for "C Trap" questions.
LGTCH
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Re: NUMBER PROPERTIES/INEQUALITY DS

by KICKGMATASS123 » Mon May 18, 2009 7:24 pm
iamcste wrote:
cramya wrote:If 500 is the multiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y, which multiple of 100 is closest to x+y?

1) x<500
2) y<400


[spoiler]OA:E[/spoiler]

The hint to this problem is in the subject... :-) Found this and wanted to share it with the group...
"500 is a multiple of 100 that is closest to x" .
-> if x were 440, the closest multiple of 100 would have been 400
-> if x were 560, the closest multiple of 100 would have been 600

So, the correct range of x values as per the qn stem is 450 < x < 550

Stem
450 < x < 550
350 < y < 450

(1) 450 < x < 500 Not sufficient
(2) 350 < y < 400 Not sufficient

Add 1 and 2
800 < x+y < 900

If x+y is 830, the closest multiple of 100 would be 800
Else if x+y is 870, the closest multiple of 100 would be 900

So, INSUFF, hence E
I dont understand how you go around picking the range??
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by cramya » Mon May 18, 2009 9:05 pm
I dont understand how you go around picking the range??
Hi PAB,

Let me take x as an example and explain

In the problem its given 500 is the closest mutiple of 100 to x

Can x be 450 -> No then 400 and 500 are equally close multiples of 100 from x

Can x be 550 -> NO then 500 and 600 are equally close multiples of 100 from x


Therefore we can say 450<x<550 (Imcaste'es sol) or

451<=x<=549 (My soln)

Similarly u can do for y. Hope this helps!

Regards,
CR
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Re: NUMBER PROPERTIES/INEQUALITY DS

by iamcste » Tue May 19, 2009 9:31 am
KICKGMATASS123 wrote:
iamcste wrote:[
I dont understand how you go around picking the range??
yes !

you have to just know this funda

If a number is close to 10, it can be any number 6 to 14

Apply this to range of X and Y , calculate range of X+Y

If we select 440, X would be close to 400 than to 500

and if we select 560 , X would be close to 600 than to 500

so, 450 < x < 550
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