In an alloy, there is 20% of copper.  To get 69 Kg of copper, how much alloy is required?

424 Kg 575 Kg 345 Kg 1736\(\frac{2}{3}\) Kg

345 Kg

20% = \(\frac{1}{5}\) → (where 1 Copper and 5 Alloy)  1 → 69  5 → 69 × 5 = 345 Kg