Question

A shopkeeper sells milk which contains 5% water. What quantity of pure milk should be added to 2 liters of milk (containing 5% water) so that proportion of water becomes 4%?

Answer 1

hii mate,
here is your answer,
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Suppose the quantity of milk to be added be x litres.

Now in 2 litres of milk there are 5% of water,
then percentage of milk = 100% - 5% = 95%

When x litres of milk is added then percentage of water in (2 + x) litres of milk = 4%

And percentage of milk in (2 + x) litres of milk = 100% - 4% = 96%

So according to the question we have;

2×95/100+x = 96/100(2+x)
⇒(190+100x)/100 = (192+96x)/100
⇒190+100x = 192+96x
⇒100x−96x = 192−190
⇒4x = 2⇒x = 24 = 0.5

Therefore the quantity of pure milk to be added is 0.5 litres.

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Hope it helps u! ! ! !
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