<span>Well 68/80 as a percent is 85 % .I got that by dividing 68 by 80 and them multiplying by 100. 100-85= 15. So therefore the dress decreased in price by 15%. </span>
18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.
<u>Step-by-step explanation:</u>
Let x = kg of 15% copper alloy
Let y = kg of 60% copper alloy
Since we need to create 90 kg of alloy we know:
x + y = 90
51% of 90 kg = 45.9 kg of copper
So we're interested in creating 45.9 kg of copper
We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:
0.15x + 0.60y = 45.9
but
x + y = 90
x= 90 - y
substituting that value in for x
0.15(90 - y) + 0.60y = 45.9
13.5 - 0.15y + 0.60y = 45.9
0.45y = 32.4
y = 72
Substituting this y value to solve for x gives:
x + y = 90
x= 90-72
x=18
Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.
Answer:
To find the unit rate, divide the numerator and denominator of the given rate by the denominator of the given rate.
Step-by-step explanation:
As an example, in this case, divide the numerator and denominator of 70/5 by 5, to get 14/1, or 14 students per class, which is the unit rate.
Answer:
Depends
Step-by-step explanation:
All triangles have 3 sides no more no less Hope this helps
Area of a rectangle: A = 24 a² b
Length: L = 8 a b²
Width: W = A / L = 24 a² b / 8 a b²
Answer: W = 3 a / b
