What is the approximate value of a truckload of ore after the gold is extracted?

• A. $720,000
• B. $1,000,000
• C. $72,000
• D. $7,200,000

Answer: (A)

The key idea is that the value of ore after gold extraction comes from how much gold is actually in that truckload, not from the ore as a rock. So you figure out the gold content first, then value it at the going price for gold.

To estimate, use: value ≈ (truckload in tons) × (ounces of gold per ton, the ore’s grade) × (price of gold per ounce). The product gives the approximate dollar value of the gold you can recover from that truckload.

In this problem, the given weight of ore and its gold grade, when multiplied by the current price of gold, come out to about $720,000, which is why that option is the best answer. If you change the weight, the grade, or the price, you’d get a different total, so the other choices correspond to different combinations of those numbers.