GmatPrep + equal

[vladmire]

Are the values in each equation suppose to equal one another like b= 4 and c = 4 could there be any other combinations

[cramya]

Given a,b,c are all positive

Question:

a(b-c) = 0 ??

If we prove a=0 or b=c(i.e. b-c=0) then a(b-c)=0

Stmt I

b-c=c-b
2b=2c
b=c

b-c is 0 We really dont need any info about a and we can safely say
a(b-c)=0
SUFF

Stmt II

b/c = c/b
b^2 = c^2

b=c (since both are positive If they were not given as positive then b=c or b=-c or c=b or c=-b)

a(b-c) will be 0

SUFF

Choose D)

[hwiya320]

question a(b-c)= 0?
for it to be true, you either nee
a=0
b-c = 0 or b=c

1. b-c = c-b
move the same letter to same side then you get 2b = 2c, divide both by 2, then you get b=c. So a(b-c) is a(0) = 0
sufficient

2. b/c = c/b

i had to modify this portion.

b^2 = c^2,

as cramya said, they're both positive. so they're equal.

your answer is D