Question 1162242
<br>
Let x be the amount (pounds) of copper.<br>
Then express the amount of each other element in terms of x.<br>
nickel: 62.5% of x, which is (5/8)x
zinc: 33.3% of x, which is (presumably) (1/3)x
lead: 5% of x, which is (1/20)x<br>
The total weight is 40 1/6 pounds, or (241/6) pounds:<br>
{{{x+(5/8)x+(1/3)x+(1/20)x = 241/6}}}
Multiply through by the least common denominator, which is 120:<br>
{{{120x+75x+40x+6x = 4820}}}
{{{241x = 4820}}}
{{{x = 4820/241 = 20}}}<br>
ANSWERS:<br>
copper: x = 20 pounds
nickel: (5/8)x = 12 1/2 pounds
zinc: (1/3)x = 6 2/3 pounds
lead: (1/20)x = 1 pound<br>
CHECK:
20 + 12 1/2 + 6 2/3 + 1 = 39+3/6+2/6 = 40 + 1/6<br>