Ametalworker has a metal alloy that is 30% copper and another alloy that is 55% copper. how many kilograms of each alloy should the metalworker combine to create 100 kg of a 50% copper alloy? the metal worker should use (blank) kilograms of the metal alloy that is 30% copper and (blank) kilograms of the metal alloy that is 55% copper. (show your work)

X+Y=100kg

X=100-Y

X*0.3+Y*0.55=100*0.5

(100-Y)*0.3+Y*0.55=50

30-0.3*Y+0.55*Y=50

0.25*Y=20

Y=80 kg

X=100-80

X=20 kg

The metal worker should use 20 kilograms of the metal alloy that is 30% copper and 80 kilograms of the metal alloy that is 55% copper.

answer: expected value of x = 1.0

step-by-step explanation:

p(x=0) = 0.25

p(x=1) = 0.50

p(x=2) = 0.25

expected value for x = 0×0.25 + 1×0.5 + 2×0.25 = 1.0