Question

50 kg of an alloy of lead and tin contains 60% lead. How much lead must be melted into

it to make an alloy containing 75% lead?​

Answer 1

Answer:

Quantity of lead in 50 kg of alloy = 60% of 50 kg = (50×60/100)kg = 30 kg.

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 = { 30+x/50+x×100}

%

∴ { 30+x/50+x×100}=75

⇒ (30+x/50+x)=75/100

⇒ (30+x/50+x)= 3/4

⇒ 4(30 + x) = 3(50 + x)

⇒ 120 + 4x = 150 + 3x

⇒ 4x - 3x = 150 - 120

⇒ x = 30

∴ quantity of lead to be added = 30 kg.

mark me as brainlist...