Question
An alloy is made of 45% lead, 35% tin, and 20% copper.
How much lead should be added to 40 kg of the alloy so that the new alloy contains 55% lead?Solution
ATQ,
Quantity of the alloy = 40 kg
Quantity of lead in 40 kg alloy = (0.45 × 40) = 18 kg
Quantity of tin in 40 kg alloy = (0.35 × 40) = 14 kg
Quantity of copper in 40 kg alloy = (0.20 × 40) = 8 kg
Let the quantity of lead to be added be x kg.
According to the question,
Quantity of lead in the new alloy = (Quantity of tin + Quantity of copper)
(18 + x) = (14 + 8)
Or, x = 22 - 18 = 4
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