in an alloy of 150 pounds of zinc and copper, there are 100 pounds of copper. How much copper must be added so that the alloy may be 10 % zinc?

Question

in an alloy of 150 pounds of zinc and copper, there are 100 pounds of copper.  How much copper must be added so that the alloy may be 10 % zinc?

amistre64 · Answer

if we setup a ratio:

  p      c    z
150:100:50  we want to know if we add k pounds of copper

150+k :100+k :50; such that 50/(150+k) = .1

anonymous · Answer

i think it is 35pounds of copper that needs to be added...

anonymous · Answer

so i have to add 200# of copper

amistre64 · Answer

well, 50 is 10% of 500, sooo  150+k=500

amistre64 · Answer

id say at least 200 :)  maybe more

anonymous · Answer

350

anonymous · Answer

ii have the answer for this

amistre64 · Answer

350 sounds about right :)

450/500 = .90

50/500 = .10

anonymous · Answer

he got it

anonymous · Answer

ok that makes sense!!  whew!!!   I am a music teacher,, I count to 4 lol.  Thanks for your help!!

amistre64 · Answer

good luck ;)