algebra

[gmat.raj]

If 4<7-x/3, which of the following must be true? [/font]
I 5<x
II |x+3|>2
III -(x+5) is positive

a) II and III only
b) I, II and III
c)II only;
d)III only;
e)I and II only


can somebody explain this please.

[touche]

4<7-x/3
or 12-7<-x
or -5<-x
or 5>x
1. No
2.|5+3|>2 yes
3.-(4+5) is positive ...No
C

[clock60]

my pick for D
i hope that it is 4<(7-x)/3
12<7-x
x<-5
(1) x<5 not for sure
(2) |x+3|>2 it true for x>-1 and x<-5 as we have both yes and no answer not must be
(3) nor compulsory to check as we have no answer none but for training purposes
-(x+5)>0
-x-5>0
-x>5
x<-5 must be true

[touche]

Yes , its D. thanks clock60.
Making very silly mistakes, Not in best of mental shape!

[gmat.raj]

Hi,

Thanks for the replies. OG answer is D

I am bit confused with the following
12<7-x
5<-x
is X> -5 Flip the sign when you divide by negative sign? Correct me if I am wrong.


Clock and touche have arrived to x<5.

This confused me with the option 1.

Please clarify.

Thanks

[clock60]

12<7-x
5<-x
is X> -5 Flip the sign when you divide by negative sign? Correct me if I am wrong.

-x>5
x<-5
x is less than -5, but not 5

[arindambanerji]

Originally Posted by clock60

my pick for D
i hope that it is 4<(7-x)/3
12<7-x
x<-5
(1) x<5 not for sure
(2) |x+3|>2 it true for x>-1 and x<-5 as we have both yes and no answer not must be
(3) nor compulsory to check as we have no answer none but for training purposes
-(x+5)>0
-x-5>0
-x>5
x<-5 must be true

I am not sure how did you discarded II

if X<-5

then X lies on a number line which is less than -5

-8...-7...-6...-5...-4....

so tha value of X should be -5.#?

|x+3| = | -5.#?+3| = |-2.#?| =+2.#?

as it is modulus

and 2.#? > 2

so IMO A

[clock60]

Originally Posted by arindambanerji

I am not sure how did you discarded II

if X<-5

then X lies on a number line which is less than -5

-8...-7...-6...-5...-4....

so tha value of X should be -5.#?

|x+3| = | -5.#?+3| = |-2.#?| =+2.#?

as it is modulus

and 2.#? > 2

so IMO A

my bad i agree with
you i missed that according problem x<-5 so st 2 valid
thank you for correcting me

[MBAchase]

IMO (D)