Question
Average weight of 8 gold coins is 20 g per coin. Average
weight of 12 silver coins is 35 g per coin. What is the average weight per coin for 20 coins?Solution
Average weight = Total weight/Number of coins ⇒ The average weight of 8 gold coins = 20 g ⇒ Total weight of 8 coins = 160 g ⇒ The average weight of 12 silver coins = 35 g ⇒ Total weight of 12 silver coins = 420 g ⇒ The average weight for 20 coins = (160 + 420)/(8 + 12) ⇒ The average weight for 20 coins = 580/20 = 29 g ∴ The average weight is 29 g per coin for 20 coins.
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