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# If (13+14+15+16)=r(19+112+115+118), then r =

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Intern
Joined: 18 Sep 2018
Posts: 1
If (13+14+15+16)=r(19+112+115+118), then r =  [#permalink]

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18 Sep 2018, 13:36
00:00

Difficulty:

55% (hard)

Question Stats:

80% (03:29) correct 20% (01:44) wrong based on 5 sessions

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If (13+14+15+16)=r(19+112+115+118), then r =

A 13
B. 43
C. 3
D. 4
E. 12

I do not understand why the answer is 3. The explanation in the Official Guide is not clear at all.

Joined: 11 Nov 2017
Posts: 117
Location: Belgium
Concentration: Technology, Operations
GMAT 1: 670 Q47 V34
GMAT 2: 750 Q50 V41
GMAT 3: 750 Q50 V41
GPA: 2.5
WE: Engineering (Aerospace and Defense)
Re: If (13+14+15+16)=r(19+112+115+118), then r =  [#permalink]

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18 Sep 2018, 13:51

if (1/3 + 1/4 + 1/5 + 1/6) = r(1/9 + 1/12 + 1/15 + 1/18), then r=

at this point you can just find the common multiple of all these numbers which in this case is: 180
changing all these to the same divisor turns the question into:

if (60/180 + 45/180 + 36/180 + 30/180) = r(20/180 + 15/180 + 12/180 + 10/180)

171/180 = r(57/180)
171/180 * 180 = 57r
r=171/57
r=3
Math Expert
Joined: 02 Sep 2009
Posts: 55624
Re: If (13+14+15+16)=r(19+112+115+118), then r =  [#permalink]

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18 Sep 2018, 20:14
sophiedes wrote:
If (13+14+15+16)=r(19+112+115+118), then r =

A 13
B. 43
C. 3
D. 4
E. 12

I do not understand why the answer is 3. The explanation in the Official Guide is not clear at all.

Discussed here: https://gmatclub.com/forum/if-1-3-1-4-1 ... 42855.html

_________________
Re: If (13+14+15+16)=r(19+112+115+118), then r =   [#permalink] 18 Sep 2018, 20:14
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