If s and t are nonzero integers, is s = 1? 1) st = 1 2) st = t

Question

If s and t are nonzero integers, is s = 1?

1) st = 1
2) st = t

IanStewart · Answer

In S1, we might have s=t=1, or s=t=-1, so S1 is not sufficient.

In S2, we have:

st = t
st - t = 0
t(s-1) = 0

which is true either if t=0, or if s=1. We are told t is not zero, so it must be that s=1, which is what the question asked, and the answer is B

.

GMATinsight · Answer

Question : Is s = 1?

Statement 1: st=1

@t=1, s=1
@t=-1, s=-1

NOT SUFFICIENT

Statement 2: st=t 
i.e. st-t = 0

i.e. t(s-1) = 0
i.e. t=0 OR s=1

But Since s and t are NON ZERO therefore s=1

SUFFICIENT

Answer: Option  B

IanStewart · Answer

t cannot be 1/2, because t is an integer. The only reason S1 is not sufficient here is because s and t might both be -1.

dheerajt94 · Answer

What I have learnt in questions like these is that you should always convert the options into simplest form.

Statement 1: s * t = 1

Simplifying in terms of s

s = 1/t (There could be an infinite amount of values for this equation)

Statement 2: s*t = t

Therefore simplifying further we have

s = t/t = 1

Answer choice  B

Kinshook · Answer

Asked: If s and t are nonzero integers, is s = 1?

1) st = 1
t, s = 1 or -1
NOT SUFFICIENT

2) st = t
t(s-1)=0
Since  t 
eq 0 
s=1
SUFFICIENT

IMO B

Posted from my mobile device

Basshead · Answer

(1)  s = t = -1  or  s = t = 1 ; INSUFFICIENT.

(2)  st = t

\frac{st}{t} = \frac{t}{t} = s = 1

SUFFICIENT.

Answer is B.

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If s and t are nonzero integers, is s = 1? 1) st = 1 2) st = t

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GMAT Data Sufficiency (DS) Questions

If s and t are nonzero integers, is s = 1? 1) st = 1 2) st = t

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