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?

Answer 1

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

Answer 2

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

Answer 3

so i have to add 200# of copper

Answer 4

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

Answer 5

id say at least 200 :) maybe more

Answer 6

350

Answer 7

ii have the answer for this

Answer 8

350 sounds about right :)

450/500 = .90

50/500 = .10

Answer 9

he got it

Answer 10

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

Answer 11

good luck ;)