Question

Hello !♥



50kg of an alloy of lead and tin contains 60% of lead. How much lead must be melted into it to make the alloy contain 75% of lead ?


Answer is 30 kg , plzz solve.


May god bless you!

Answer 1

Hey there !

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Quantity of lead in 50 kg of alloy

=> 60% of 50 kg



$\lgroup 50 \times \frac{60}{100} \rgroup \: kg \\ \\ \lgroup 5 \cancel0 \: \times \frac{6 \cancel0}{1 \cancel0\cancel0 }\rgroup \\ \\ = > \bold{ 30kg}$

Let the required quantity of lead to be added be x kg.

Then, weight of lead = ( 30 + x ) kg.

And, weight of new alloy = ( 50 + x ) kg.

percentage of lead in new alloy

$= \lbrace \frac{(30 + x)}{(50 + x)} \times 100 \rbrace \% \\ \\ \therefore \: \frac{(30 + x)}{(50 + x)} \times 100 = 75 \\ \\ = > \frac{(30 + x)}{(50 + x)} = \frac{ \cancel{75} \: {}^{3} }{ \cancel{100} \: {}^{4} } \\ \\ = > \frac{(30 + x)}{(50 + x)} = \frac{3}{4} \\ \\ = > 4(30 + x) = 3(50 + x) \\ \\ = > 120 + 4x = 150 + 3x \\ \\ = > 4x - 3x = 150 - 120 \\ \\ = > x = 30$

Therefore,

Quantity of lead to be added = 30 kg.

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Thanks for the question !

Answer 2

Answer:

answer is x= 30 kg. please mark as brainlist