Answer:
He did 9 times 10 instead of 9 times 100.
Answer:
The cost of extracting the first 50 tons of copper is $151,000.
Step-by-step explanation:
Start-up costs of $150,000.
For the 50 tons of cooper.

So

1 thousand dollars.
So
$150,000 + $1,000 = $151,000
The cost of extracting the first 50 tons of copper is $151,000.