Answer
Percentage of Copper in ore = 25% = 0.25
Required copper = 91 metric ton
Required Ore = 91/0.25 x 100 = 36,400 metric tons
Work Step by Step
Percentage of Copper in ore = 25% = 0.25
Required copper = 91 metric ton
Required Ore = 91/0.25 x 100 = 36,400 metric tons