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 By: karseng (offline)  Sunday, March 18 2012 @ 05:30 AM CDT (Read 1458 times)
karseng

Albert & Benny had \$282. Benny had \$4 more than Albert. Benny spent 1/2 as much as Albert and was left with twice as much as Albert. How much did Benny spend?

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Registered: 04/20/11
Posts: 3

 By: RachelAng (offline)  Tuesday, March 27 2012 @ 02:02 AM CDT
RachelAng

282 - 4 = 278
278 / 2 = 139

A has 139
B has 139 + 4 = 143.

A spends S, then B spends S/2 or A spends 2S, B spends S.

A: 1 unit left + 2S = 139
B: 2 units left + S = 143

So 3S = 139 + 139 - 143
S = 45

B spent \$45

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Registered: 01/23/11
Posts: 4

 By: echeewh (offline)  Tuesday, March 27 2012 @ 07:07 PM CDT
echeewh

Alternative solution:

<before>
A= ( 282 - 4 ) / 2 = 139
B= 139 + 4 = 143

<spent>
A : B
2 : 1

<after>
A : B
1 : 2

139 - 2u --> 1p ----- (1)
143 - 1u --> 2p ----- (2)

Applying Simultaneous Concept / Compare & Replace method:

Since question is only interested in finding how much did Benny spend ( 1u ), we have:

(1) x 2: 278 - 4u --> 2p ----- (3)
(3) - (2): 3u --> 135
1u --> 135 / 3
= \$45
==========================

Hope this helps.

Cheers

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Registered: 04/21/11
Posts: 627

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