In one day, Juan sends Keith three times as many...

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In one day, Juan sends Keith three times as many messages as he sends Laurence, and Laurence sends Missy 4.5 times as many messages as he received from Juan. If Missy received 18 messages from Laurence, how many messages does Keith recive from Juan?

A. 3
B. 12
C. 16
D. 18
E. 56

The OA is B.

Please, can any expert explain this PS question for me? I have many difficulties to understand why that is the correct answer. Thanks.

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by Jay@ManhattanReview » Tue Dec 19, 2017 1:25 am
swerve wrote:In one day, Juan sends Keith three times as many messages as he sends Laurence, and Laurence sends Missy 4.5 times as many messages as he received from Juan. If Missy received 18 messages from Laurence, how many messages does Keith recive from Juan?

A. 3
B. 12
C. 16
D. 18
E. 56

The OA is B.

Please, can any expert explain this PS question for me? I have many difficulties to understand why that is the correct answer. Thanks.
Say the number of messages Juan sends Keith is given by jk, the number of messages Juan sends Laurence is given by jl.

Thus, jk = 3jl ---(1)

Say the number of messages Laurence sends Missy is given by lm.

Thus, lm = 4.5jl ---(2); the number of messages Laurence received from Juan is the same as the number of messages Juan sends Laurence = jl

Missy received 18 messages from Laurence is the same as the number of messages Laurence sends Missy = lm = 18

Thus, from (2), we have 18 = 4.5jl => jl = 4

From (1) jk = 3jl, we have jk = 3*4 = 12 messages.

The number of messages Juan sends Keith = 12 is the same as the number of messages Keith recive from Juan.

The correct answer: B

Hope this helps!

-Jay
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by Scott@TargetTestPrep » Fri Sep 13, 2019 3:26 pm
swerve wrote:In one day, Juan sends Keith three times as many messages as he sends Laurence, and Laurence sends Missy 4.5 times as many messages as he received from Juan. If Missy received 18 messages from Laurence, how many messages does Keith recive from Juan?

A. 3
B. 12
C. 16
D. 18
E. 56

The OA is B.

Please, can any expert explain this PS question for me? I have many difficulties to understand why that is the correct answer. Thanks.
Since Missy received 18 messages from Laurence and this is 4.5 times as many messages as he received from Juan, Laurence receives 18/4.5 = 4 messages from Juan. Since Juan sends Keith three times as many messages as he sends Laurence, Keith receives 4 x 3 = 12 messages from Juan.

Answer: B

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