If r is represented ....

[factor26]

If r is represented by the decimal 0.t5 what is the digit t ?

1) r < 1/3
2) r < 1/10

i researched this question on the btg site but it doesnt look like a lot of people answered it ... PLEASE HELP

OG answer is b

[kanwar86]

If r is represented by the decimal 0.t5 what is the digit t ?

1) r < 1/3
2) r < 1/10

i researched this question on the btg site but it doesnt look like a lot of people answered it ... PLEASE HELP

OG answer is b

Option 1, r<1/3 or r<0.33 (aprox)
As r= 0.t5; Here t can be 0,1 or 2. All of them are less than 0.33 (No unique solution)
Hence, 1) is not sufficient.
Option 2, r<0.1
Now, only t=0 satisfies 0.05<0.1
Hence, option 2 is sufficient. Answer is B)

[pemdas]

r=0.t5
st(1) r<1/3 OR 0.t5<1/3, 3*0.t5<1 which is equivalent to 0.(t+1)5<1. It's clear that t can be {0,1,2,3,4,...} Not Sufficient
st(2) r<1/10 by applying the same logic as in st(1) we get 10*0.t5<1 and t.5<1 which is only possible for t=0 Sufficient

ans is B

If r is represented by the decimal 0.t5 what is the digit t ?

1) r < 1/3
2) r < 1/10

i researched this question on the btg site but it doesnt look like a lot of people answered it ... PLEASE HELP

OG answer is b

[Anurag@Gurome]

If r is represented by the decimal 0.t5 what is the digit t ?

1) r < 1/3
2) r < 1/10

i researched this question on the btg site but it doesnt look like a lot of people answered it ... PLEASE HELP

OG answer is b

(1) r < 1/3 implies r can be 0.25, 0.15, or 0.05. Since we do not get a definite answer, so (1) is NOT sufficient.

(2) r < 1/10 or r < 0.10 implies r can be 0.05, so the only possibility for digit t is 0; SUFFICIENT.

The correct answer is B.

[factor26]

@ANURAG ... EXCELLENT EXPLINATION ... SHORT AND TO THE POINT ... MANY THANKS!

[mzalmati]

I think the correct answer should be "E". Because you are not restricted to positive values. So, even the 2nd statement is insufficient.
For instance: if r =0.05, then t=0
if r = -0.15, then t = 1 and so on.
It should be mentioned that the decimal number is positive, in that case the right answer would be "B"

[shawndx]

I think the correct answer should be "E". Because you are not restricted to positive values. So, even the 2nd statement is insufficient.
For instance: if r =0.05, then t=0
if r = -0.15, then t = 1 and so on.
It should be mentioned that the decimal number is positive, in that case the right answer would be "B"

I also thought the same initially, but upon further inspection the question stem indirectly tells you that you are restricted to positive values since R=0.t5 and therefore it is not possible for R=-0.t5

with that logic if r is less than 0.1 and it has to have a 5 in the 100th's digit the only possible value for r would then be 0.05---> t is equal to 0 and so B is sufficient

[snigdhakul]

I also thought the same initially, but upon further inspection the question stem indirectly tells you that you are restricted to positive values since R=0.t5 and therefore it is not possible for R=-0.t5

with that logic if r is less than 0.1 and it has to have a 5 in the 100th's digit the only possible value for r would then be 0.05---> t is equal to 0 and so B is sufficient

Can we be sure that in GMAT if the question is given in the form of R=0.abc then we should restrict ourselves to only positive value and not assume the negative values?