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John bought 7 rulers and 12 magnets with 1/3 of his savings. The

cost of a magnet is 3 times the cost of a ruler. He used 2/3 of his 

remaining allowance to buy more rulers. Hence, how many rulers did

he buy altogether?

 Sep 24, 2021
 #1
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Let the cost of one ruler be:  x

Therefore cost of 1 magnet is: 3x
 

 

 

Let his saving be: S

Now:

7x+12(3x)=S/3

7x+36x=S/3

43x=S/3

x=S/129

S=129x

Now we have to find the number of rulers purchased by him in 2S/9

2/9S=2/9*129x

2/9S≈$28.67x

Hence John bought 28  rulers.
 

 Dec 4, 2021

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