If a, b, and c are positive distinct integers, is (a/b)/c an

Question

If a, b, and c are positive distinct integers, is (a/b)/c an integer?
c = 2
a = b + c

ronneyc · Answer

Hi,

the equation can be rewritten as (ac/b).

Stat. 1 is not sufficient let's take a=1, b=3 and c=2 the result is not an integer. And if we take b=4 the result is an integer.

Stat. 2 gives us  /b = b + (c²/b).
if c=2 and b=3, the result is not an integer.
if c=2 and b=4 the result is an integer => thus stat. 2 not sufficient

Combining 1 & 2 we have both cases (integer and non integer)

My ans. is E

ronneyc · Answer

I missed (a) in stat 1 ... take b=4 and a=6

Ravshonbek · Answer

B 
1. doesnt give info about others
2. suff.

(a/b)/c=a/bc

(b+c)/bc

 1/b+1/c 

since b and c are disticnt positive integers and b is not equal to c 
the expression cannot be an integer

Ravshonbek · Answer

tricky.
tempting to say C but it is B i think.

winniephan · Answer

Welldone Rav. Got B 2!

Ferihere · Answer

Again late  B

done_gre_now_gmat · Answer

B.

Q: (a/b)/c = (a/bc) 
S1: Insuff
S2: a = b+c ==> (b+c)/bc - is always a fraction for any set of distinct positive integers - Suff

Tibby · Answer

A: Insuff. Given a, b are distinct integers, a/b must be an even integer. a=4, b=1 - true. a=9, b=3 - false. Both, true & false possible. Hence, inconclusive.
B: On simplifying, given b, c are distinct integers, (1/b + 1/c) must be an integer. For any b,c where b <> c, this is false. Hence, conclusive.

Thus, B.

If a, b, and c are positive distinct integers, is (a/b)/c an

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