An alloy contains 40 % of silver, 30% of nickel and 30% of copper. How much silver should be added to 25 kg of the alloy so that the new alloy contains 50% of silver?
Answer & explanation
Correct answer: option 2
ATQ,
⇒ Silver = \(\frac{25\;×\;4}{100}\) = 10
⇒ Nickal = \(\frac{25\;×\;3}{10}\) = 7.5
⇒ Copper = \(\frac{25\;×\;3}{10}\) = 7.5
Let x kg silver be added;
⇒ \(\frac{10 + x}{25 + x}\) = \(\frac{50}{100}\)
⇒ 20 + 2x = 25 + x
⇒ x = 5