Answer:
Use 49 ounces of the 14% allow and 41 ounces of the 23% alloy.
Step-by-step explanation:
Each ounce of the 14% copper contains 0.14 ounce of pure copper.
Each ounce of the 23% copper contains 0.23 ounce of pure copper.
Each ounce of the 18.1% copper contains 0.181 ounce of pure copper.
Use x ounces of the 14% and y ounces of the 23% to make 90 ounces of 18.1% alloy.
x+y = 90
y = 90-x
0.14x + 0.23y = 0.181·90
0.14x + 0.23(90-x) = 16.29
0.14x + 20.7 - 0.23x = 16.29
-0.09x + 20.7 = 16.29
4.41 = 0.09x
x = 49
y = 90-x = 41
Use 49 ounces of the 14% allow and 41 ounces of the 23% alloy.
Divide the perimeter by 2, this will give you the sum of one length and one width.
68/2 = 34 yards
Now the length is 10 yards more, so subtract 10 from the 34 and divide by 2 again:
34 - 10 = 24
24 /2 = 12
The width is 12 yards.
The length is 12 + 10 = 22 yards.
Answer:
1 cm = 20 km
so 3.5 cm would equal : 3.5 * 20 = 70 km
hope it helps ;)
Step-by-step explanation:
As a fraction it is 466666/1000000
