A copper alloy that is 40% copper is to be combined with a copper alloy that is 80% copper to produce 120 kilograms of an alloy that is 70% copper. How many kilograms of each alloy must be used?

Question

anonymous · Answer

we need 70% of 120 kgs  = 84 kgs copper
0.4x + 0.8y = 84              where  x and y are weights of two alloys
x + y = 120
solve to get the answer

anonymous · Answer

haha cant you just give me the answer :P

anonymous · Answer

jimmy i got x equals 30 and y eqyuals 90 is that right jimmy boy? :p

anonymous · Answer

yes

anonymous · Answer

30 * 0.4 = 12 kgs
90*0.8 = 72 kgs

totals   12 + 72 =84 
30 + 90 = 120

anonymous · Answer

dead right