akashkumar1987 wrote:When the positive number a is rounded to the nearest tenth, the result is the number b. What is the tenths digit of a?
(1) When a is rounded to the nearest integer, the result is less than a.
(2) When b is rounded to the nearest integer, the result is greater than b.
Statement 1: When a is rounded to the nearest integer, the result is less than a.
Thus, the tenths digit of
a must be LESS THAN 5, so that
a rounds DOWN to the nearest integer:
a = X.0, X.1, X.2, X.3, X.4.
Since the tenths digit of a can be different values, INSUFFICIENT.
Statement 2: When b is rounded to the nearest integer, the result is greater than b.
Thus, the tenths digit of b must be GREATER THAN OR EQUAL TO 5, so that b rounds UP to the nearest integer:
b = X.5, X.6, X.7, X.8, X.9.
It's possible that a = X.49, so that
a rounded to the nearest tenth yields b = X.5.
It's possible that a = X.59, so that
a rounded to the nearest tenth yields b = X.6.
Since the tenths digit of a can be different values, INSUFFICIENT.
Statements combined:
In statement 1, the greatest possible tenths digit for a = X.4.
In statement 2, the least possible tenths digit for b = X.5.
Thus, it must be true that a ≥ X.45, so that
a rounded to the nearest tenth yields b = X.5, the least possible value for b.
Thus, the tenths digit of a must be 4.
SUFFICIENT.
The correct answer is
C.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3
