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Sajjad1994
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If V = 12R / (r + R) , then R = A. Vr / (12 - V) B. Vr + V /12 C. V 12 Feb 2017, 04:45
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A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

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5% (low)

Question Stats:

86% (01:08) correct 14% (02:06) wrong based on 78 sessions

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If V = 12R / (r + R) , then R =

A. Vr / (12 - V)
B. Vr + V /12
C. Vr - 12
D. V / r - 12
E. V (r + 1) /12

Source: Major Tests
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A
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If V = 12R / (r + R) , then R = A. Vr / (12 - V) B. Vr + V /12 C. V 12 Feb 2017, 06:29
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SajjadAhmad
Source: Major Tests

If V = 12R / (r + R) , then R =

A. Vr / (12 - V)
B. Vr + V /12
C. Vr - 12
D. V / r - 12
E. V (r + 1) /12
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Hey,

PFB the solution.

This is a simple re-arrangement question.


    • \(V = \frac{12R}{(r + R)}\)

    • Multiplying both sides by \((r + R)\), we get -

      o \(V * (r + R) = 12R * \frac{(r+R)}{(r+R)}\)

      o \(Vr + VR = 12R\)

      o Subtracting both sides by \(VR\), we get –

         \(Vr + VR – VR = 12R – VR\)

         Therefore, \(R = \frac{Vr}{(12- V)}\)

      o Correct Answer is Option A


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If V = 12R / (r + R) , then R = A. Vr / (12 - V) B. Vr + V /12 C. V 12 Feb 2017, 06:51
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SajjadAhmad
Source: Major Tests

If V = 12R / (r + R) , then R =

A. Vr / (12 - V)
B. Vr + V /12
C. Vr - 12
D. V / r - 12
E. V (r + 1) /12
Show more


\(rV + RV = 12R\)

Or, \(12R - RV = rV\)

Or, \(R ( 12 - V ) = rV\)

Or, \(R = \frac{rV}{(12 - V)}\)

Hence, correct answer will be (A) Vr / (12 - V)
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If V = 12R / (r + R) , then R = A. Vr / (12 - V) B. Vr + V /12 C. V 12 Feb 2017, 21:16
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Hi SajjadAhmad,

This question can be solved by TESTing VALUES.

We're told that V = 12R / (r + R) and we're asked for the value of R.

IF....
R = 2
r = 4
V = (12)(2)/(4+2) = 24/6 = 4

So we're looking for an answer that equals 2 when r = 4 and V = 4

Answer A: 16/8 = 2 This IS a match
Answer B: 16 + 4/12 = 16 1/3 NOT a match
Answer C: 16 - 12 = 4 NOT a match
Answer D: 4/4 - 12 = -11 NOT a match
Answer E: 4(5)/12 = 20/12 NOT a match

Final Answer:
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A

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If V = 12R / (r + R) , then R = A. Vr / (12 - V) B. Vr + V /12 C. V 19 Feb 2017, 11:56
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Answer is A
But I doubt it that it is of 600 level man
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If V = 12R / (r + R) , then R = A. Vr / (12 - V) B. Vr + V /12 C. V 20 Aug 2021, 06:32
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