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Sub 505 Level|   Geometry|      
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If a = 100, what is the value of c? 15 May 2018, 07:15
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94% (00:45) correct 6% (00:28) wrong based on 172 sessions

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If a = 100, what is the value of c?

(1) b = 30
(2) f = 50


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D
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If a = 100, what is the value of c? 15 May 2018, 07:26
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IMO is D.. first statement is sufficient as angle d will be 100 and b is 30 so 180-100-30 = 50 I. E angle C. Second statement as angle for is 50 so angle can is also 50

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If a = 100, what is the value of c? 15 May 2018, 10:56
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If a = 100, what is the value of c?

(1) b = 30
(2) f = 50


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DxjVcg8.png
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In the diagram, because of vertically opposite lines, angle a = angle d, angle b = angle e and angle c = angle f. Also sum of these 6 angles will be 360 degrees. We are given that a = d =100. So a+d = 200 and c+f+b+e = 160. Or we can say 2c + 2b = 160 or c+b = 80 degrees. We need to find c.

(1) b=30. So c = 80-30 = 50 degrees. Sufficient.

(2) f=50, but f is same as c. So c = 50 degrees. Sufficient.

Hence D answer
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If a = 100, what is the value of c? 16 May 2018, 01:13
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If a = 100, what is the value of c?

(1) b = 30
(2) f = 50


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DxjVcg8.png
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Statement 1: b = 30
a + b + c = 180. Angle in a straight line is 180.
From stem, a = 100; from statement 1 b = 30.
So, 100 + 30 + c = 180 or c = 50.
Statement 1 alone is sufficient.

Statement 2: f = 50
f + a + b = 180. Angle in a straight line is 180.
From stem, a = 100; from statement 2 f = 50.
So, 50 + 100 + b = 180
or b = 30.
If we know b is 30, we can find c to be 50 using the method used for statement 1.

Statement 2 alone is also sufficient.

Choice D is the answer.
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If a = 100, what is the value of c? 31 Mar 2024, 06:39
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Hello from the GMAT Club BumpBot!

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