Bunuel wrote:

On the line above, if AB < BC < CD < DE, which of the following must be true?

(A) AC < CD

(B) AC < CE

(C) AD < CE

(D) AD < DE

(E) BD < DE

Attachment:

2017-07-12_1253.png

Given AB<BC<CD<DE

Please note that all the values which AB, BC, CD or DE take will be positive. Lets assume

AB = a

BC=a+x

CD=a+x+y

DE=a+x+y+z

All a,x,y,z are positive

(A) AC < CD => AB+BC<CD => a+a+x<a+x+y (a could be greater than y) Nope

(B) AC < CE => AB+BC<CD+DE => a+a+x<a+x+y+a+x+y+z => 0<y+x+y+z and since x,y,z is positive..this is our answer

(C) AD < CE => AB+BC+CD<CD+DE => AB+BC<DE => a+a+x<a+x+y+z (a could be greater than y+z) Nope

(D) AD < DE => AB+BC+CD < DE => a+a+x+a+x+y<a+x+y+z (2a+x could be larger than z) Nope

(E) BD < DE => BC+CD<DE => a+x+a+x+y<a+x+y+z (a+x could be larger than z) Nope

Hence B

We can also use smart numbers like a=6, x=2, y=3, z=4

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Thanks

Luckisnoexcuse