Sterling silver is an alloy made by combining silver with copper in a ratio of 23 to 2. How much copper should be combined with 70 kg of silver to make sterling silver?

1 Answer
Dec 31, 2016

Answer:

#2Cuharr23Ag#. Question is #?Cuharr70Ag#
A ratio question.

Explanation:

#2div23=Xdiv70# or #2/23=X/70#

Cross-multiply:
#23X=2*70->X=(2*70)/23~~6.09# kg of copper.

Another way:

#70#kg amounts to #70/23=3,0347...# times as much as #27#

So we need #3,0347...# times as much copper (same answer)