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If the two horizontal lines in the figure provided are parallel, what [#permalink]
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11 Sep 2015, 02:23
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61% (01:25) correct 39% (01:43) wrong based on 146 sessions
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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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11 Sep 2015, 03:13
Answer: (B) (2) alone is sufficient. Let's consider these onebyone: (1) a+f = 180This does not provide any information we don't already have. If the lines are parallel, the following equalities hold  a = d (opposite angles) a = e (corresponding angles) b + d = 180 a + b = 180 e + f = 180 d + f = 180 b = f and so on. So, we already know that a + f = 180. This is not helpful in finding (a + f + d) – (e + h), as we don't know any of these values. (2) a  f = 60This is SUFFICIENT: a + f = 180 (because a = d and d+f = 180, which is because d + b = 180 and b = f) a  f = 60 So, 2a = 240 or a = 120 Also, a = d so d = 120; f = 180  a = 60 ; e = a = 120 ; h = e = 120 So, we can evaluate (a + f + d) – (e + h). Hence sufficient. Answer: (B)
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If the two horizontal lines in the figure provided are parallel, what [#permalink]
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Updated on: 11 Sep 2015, 05:03
Question Stem is a + f + d  e  h = ? Since , a = e & h = d ( Corresponding angles ) 1) Question Stem can be re written as following a + f + d  a  d ( Substituting e & h with a & d ) a + f + d  a  dSO the question is asking for the value of angle f alone.2 ) Statement 1. a + f = 180. As this information can be derived from the diagram itself, it is no additional information. Hence Insufficient. 3) Statement 2. a  f = 60................. Eq 1. Since we know a + f = 180 ( sum of angles on same straight line ) .........................Eq 2. Adding Eq 1 & Eq 2 => a = 120. This is suffucient information to find what the questions seeks. Therefore sufficient. Ans is B.



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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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11 Sep 2015, 03:46
If the two horizontal lines in the figure provided are parallel, what is (a + f + d) – (e + h)?
(1) a + f = 180
(2) a – f = 60
answer (B) (a + f + d) – (e + h)? a=e & d=h ( corresponding angles)
so a+f+dad=f To find f, we need two equations but we know that a+f=180 So we only need af=60



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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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11 Sep 2015, 06:57
If the two horizontal lines in the figure provided are parallel, what is (a + f + d) – (e + h)? (1) a + f = 180 (2) a – f = 60 (a + f + d) – (e + h) = a + f + d  d a = f on applying alternate angle theory  as e =d and a =h so f =? st 1. a+f =180 hence 1 not sufficient st 2. a f =60 and f =b ( corresponding angle ) so ab =60  a and a+b = 180  b(angle on a straight line equal 180 ) solving a and b we get a = 240/2= 120 and therefore f = 60 B sufficient Ans
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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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11 Sep 2015, 12:49
The question stem says the horizontal lines are parallel.
Using this information we can deduce, a = d (1) (opposite angles)
a= e (2) (corresponding angles)
e= h (3) (opposite angles) , therefore a = h
d + f = 180 from (1) a + f = 180  (4)
using this info in the equation (a + f + d) – (e + h)
180 + a  2a => 180  a  (5)
Statement 1:
a + f = 180 => same as eq. (4) . No new info. Cannot get the value  Insufficient
statement 2
a – f = 60  (6) from (4) and (6) can find the value of a substitute in (5) we can find the value of (a + f + d) – (e + h)
Ans B => Statement 2 sufficient



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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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12 Sep 2015, 05:28
answer is B.
f=c (parallel lines having same interception) hence, a+c or a+f=180 B gives that af=60
solving for both we get the vales for a and f.



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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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12 Sep 2015, 10:13
Bunuel wrote: If the two horizontal lines in the figure provided are parallel, what is (a + f + d) – (e + h)? (1) a + f = 180 (2) a – f = 60 Kudos for a correct solution. Given : From Parallel Line case, a = d = e = h b = c = f = gQuestion : what is (a + f + d) – (e + h) = (a+f+a)  (a+a) = f = ?Statement 1: a + f = 180a is Unknown Hence f can't be calculated Also, a+f=180 is a Universal Truth (Supplementary angles) and no extra information so this can't be used to answer the question because we are expected to know about this informationNOT SUFFICIENT Statement 2: a  f = 60Also, We know a+f=180 (Supplementary angles) i.e. a = 120 and f = 60 SUFFICIENT Answer: option B
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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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14 Sep 2015, 07:55
Bunuel wrote: If the two horizontal lines in the figure provided are parallel, what is (a + f + d) – (e + h)? (1) a + f = 180 (2) a – f = 60 Kudos for a correct solution. GROCKIT OFFICIAL SOLUTION:This question solely relies on our knowledge of angle measures and parallel lines. Angles a and b are complementary (add up to 180, a straight line), and angles b and f are congruent, so we already know that a + f = 180 without Statement (1) telling us. (a + f + d) – (e + h) = a + f + d – e – h = 180 – h. Since we do not know the exact value of h (the difference between the obtuse and acute angles), Statement (1) is not sufficient. Statement (2) gives us the difference between the obtuse and acute angle, and so it is sufficient.
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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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15 Sep 2015, 09:32
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution. If the two horizontal lines in the figure provided are parallel, what is (a + f + d) – (e + h)? (1) a + f = 180 (2) a – f = 60 Transforming the original condition and the question, we have a=d=e=h thus (a + f + d) – (e + h)?> f=?. a+f=180 we have 2 variables (a,f), and 1 equation (a+f=180) therefore we need 1 more equation. Therefore there is high probability that D is the answer In case of 1), a+f=180 is the repetition of the original condition. Therefore the condition is not sufficient. In case of 2), af=60 and a+f=180 gives us 2f=120, f=60. Therefore the condition is sufficient, and the answer is B.
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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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23 Oct 2015, 10:33
This is what you call a trick question.... How I fell for it... C trap question ...



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Re: If the two horizontal lines in the figure provided are parallel, what [#permalink]
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11 Apr 2017, 04:50
nikhiljd wrote: This is what you call a trick question.... How I fell for it... C trap question ... A + B = 180 B = F A + F = 180 Therefore you should skip this option first of all




Re: If the two horizontal lines in the figure provided are parallel, what
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11 Apr 2017, 04:50






