10.5 lbs of pure copper in the 200 lb chunk.

200 lbs x 5.25% (.0525) = 10.5 lbs

I see that you've clearly found out a way of finishing your homework quickly,not really appreciable way though.But still I can help you with steps and you have to do the calculation alright.I bet you would use the calculator but still remember you will have to learn things for your exams

The question says

5.25 % of 200 pounds is copper

5.25% is 5.25/100 so,

5.25/100 of 200

replace 'of with * sing

that is (5.25/100 )*200

IN BOTH THE ANSWER I'VE GIVEN YOU DO THE CALCULATIONS IN THE BRACKET FIRST TO GET THE RIGHT ANSWER . (I thought you may not know)

The question says

5.25 % of 200 pounds is copper

5.25% is 5.25/100 so,

5.25/100 of 200

replace 'of with * sing

that is (5.25/100 )*200

IN BOTH THE ANSWER I'VE GIVEN YOU DO THE CALCULATIONS IN THE BRACKET FIRST TO GET THE RIGHT ANSWER . (I thought you may not know)

Thanks 1050