Answer:
Step-by-step explanation:
The order of the top three are
In that order. Copper is used where there is some tolerance for corrosion for it much cheaper than the other two. Gold is used where corosion is a consideration because Gold does not tarnish. Silver is used when conductivity is the primary concern.
Aluminum was tried in house wiring. It is very brittle. I think it was abandoned.
Answer:
12
Step-by-step explanation:
60% of 30 is 18 so 40% is 12
Answer:
Not accurate
Step-by-step explanation:
3+9+9=21