GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
J = x rounded to the nearest TENTH, and
[#permalink]
31 May 2018, 05:41
31 May 2018, 05:41
00:00
Question Stats:
71% (02:10) correct
28% (02:55) wrong based on 7 sessions
Hide Show timer Statistics
J = x rounded to the nearest TENTH, and K = x rounded to the nearest THOUSANDTH. If 0 < x < 1, what is the greatest possible value of J – K?
A) 0.005
B) 0.0055
C) 0.05
D) 0.0505
E) 0.0555
A) 0.005
B) 0.0055
C) 0.05
D) 0.0505
E) 0.0555
Re: J = x rounded to the nearest TENTH, and
[#permalink]
31 May 2018, 22:51
31 May 2018, 22:51
1
Value of x when not rounded is somewhere between 0 and 1.
We know that J can have a value of 0.1 to 0.9 because x is rounded to tenth.
But we are also required to find J-K when it is maximum we need to make sure that J is maximum so J can only be 0.9
Coming to K, K can have a value such as 0.abc where a,b and c are placeholders. Because J is rounded to thousandth.
But we should make sure that K is as small as possible for J-K to be maximum.
How can we round O.abc to O.a such that O.a is 0.9 ?
we know that 0.85 is the least number when rounded that gives us 0.9 hence 0.abc can be rewritten as 0.85c
at this point we should make sure that c is least as well that way K is least hence c = 0
Therefore, K = 0.850
Hence, J-K = 0.9-0.850 = 0.05
option C
We know that J can have a value of 0.1 to 0.9 because x is rounded to tenth.
But we are also required to find J-K when it is maximum we need to make sure that J is maximum so J can only be 0.9
Coming to K, K can have a value such as 0.abc where a,b and c are placeholders. Because J is rounded to thousandth.
But we should make sure that K is as small as possible for J-K to be maximum.
How can we round O.abc to O.a such that O.a is 0.9 ?
we know that 0.85 is the least number when rounded that gives us 0.9 hence 0.abc can be rewritten as 0.85c
at this point we should make sure that c is least as well that way K is least hence c = 0
Therefore, K = 0.850
Hence, J-K = 0.9-0.850 = 0.05
option C
gmatclubot
Re: J = x rounded to the nearest TENTH, and [#permalink]
31 May 2018, 22:51
Moderators:
