Puzzle 60 - All that glitters ..

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By the way, gold ingot is a gold bar. I googled.

This is quite a simple puzzle. 

Solution : 

Let us say the weight of of ingot is x kg. 

On one side of scale is 1 ingot = x kg

On the other side is 1/2 ingot and 3/4kg weight = x/2+3/4

As they balance,   x = x/2 + 3/4

Transferring x/2 to LHS, we get 

x - x/2 = 3/4 

x/2 = 3/4 

x = 2* 3/4 = 1.5 kg

 

Bonus puzzle :

As we are talking about balanced scales,

A set of scales is in balance. On one side are 3½ bags of rice, on the other, 1¾
bags of rice and a ¼ kilogram weight. How heavy is a bag of rice?

Solution : 

Let us again take the weight of 1 bag or rice as x kg (we buy 25kg bags :) ) 

So 3.5x = 1.75x+0.25

Transferring 1.75x to LHS, 

(3.5 - 1.75)x = 0.25

1.75x = 0.25

Multiplying both the sides by 100,

175x = 25

x = 25/175 = 1/7 kg = 0.14285714kg


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