Hi All,
On Test Day, certain content knowledge is a must (math formulas, grammar rules, etc. ) while other knowledge can be really helpful (fraction-to-decimal conversations, perfect squares, "style" rules, knowing what the common wrong answers "look like", etc.)
Here, knowing your basic fraction-to-decimal conversations would help you to answer this question really easily.
The prompt tells us that N is a POSITIVE INTEGER less than 10. So N is 1 to 9, inclusive. We're asked for the value of N.
Fact 1: N is the tenth's digit of the decimal representation of 1/N
Since N can only be 9 different integers, I'm going to write them all down (in 1/N format) for reference:
1/1 = 1.00
1/2 = 0.50
1/3 = 0.333.....
1/4 = 0.25
1/5 = 0.20
1/6 = 0.166.....
1/7 = 0.142.....
1/8 = 0.125
1/9 = 0.111.....
So, what value of N matches the TENTH'S digit of it's matching fraction?
ONLY 1/3. N IS 3.
Fact 1 is SUFFICIENT
Fact 2: N is the hundredth's digit of the decimal representation of 1/N
Using the same information from above, we can now look for a matching HUNDREDTH's digit...
1/3 AND 1/6 fit this description. N can be 3 or 6.
Fact 2 is INSUFFICIENT
Final Answer:
GMAT assassins aren't born, they're made,
Rich