1.The price Sally paid for the bicycle was (0.9)x dollars, excluding the 10 percent sales tax.
we do not know the original price of the bicycle to determine if it was less than x and we really never know if 0.9x+10% of sales tax is less or more than x as total amount is not given and never mentioned anywhere that it is x.Insufficient

2. The price Sally paid for the bicycle was $170. excluding sales tax. again here we do not know x.Insufficient

1+2>> 0.9x=170>> for 188.88 (excluding sales tax) he paid 170 but nowhere it is mentioned that it is total amount and thus tax cant be calculated to determine if it is less than x or more than x, Insufficient

Ans E
_________________

If you like my posts appreciate them with Kudos
Cheers!!

The correct answer is A.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics