Answer:
58.33 lbs.
Step-by-step explanation:
There are already 25 lbs of alloy of copper
Of this 25 lbs, 20% is pure i.e. copper content = 25(0.5) = 5lbs.
Now available is
Copper Other metals
5 lbs 20 lbs
Let x lb of 30% copper is added.
Then new alloy will have 5+0.3x lb copper in total of 25+x lbs
Percentage pure = 
Simplify to get

Hence answer is 58.33 lbs should be added.
Answer:
11.06 meters
Step-by-step explanation:
Given that
The height of a regulation soccer goal is 2.4 meters
And, the distance is 10.8 meters
We need to find out the hypothesis
Here we applied the pythagoreans theorem
So,
= √ (2.4m) ^2 + (10.8 m) ^2
= √5.76 m^2 + 116.64m^2
h = 11.06 m
Hence, the hypothesis is 11.05 meters
Answer:
Step-by-step explanation:
x^2+120=0 can be rewritten as x^2 = - 120. Taking the square root of both sides, we get x = plus or minus i*√120 = plus or minus i*√4√30, or
x = plus or minus i*2√30
So the correct answer choice here is "None of the above."
Answer:
(a) 12.96 ft²
(b) 21.5 in²
Step-by-step explanation:
(a) For the first diagram
Area of the shaded region (A) = Area of Tripezium- area of circle
A = [1/2(a+b)h]-[πr²]............... Equation 1
Where a and b are the parallel side of the tripezium respectively, h = height of the tripezium, r = radius of the circle.
From the diagram,
Given: a = 15 ft, b = 6 ft, h = 12 ft, r = h/2 = 12/2 = 6 ft.
Constant: π = 3.14
Substitute these values into equation 1
A = [12(15+6)/2]-(3.14×6²)
A = 126-113.04
A = 12.96 ft²
(b) For the second diagram,
Area of the shaded region (A') = Area of square- area of circle
A' = (L²)-(πr²)............. Equation 2
Where L = lenght of one side of the square, r = radius of the circle
From the diagram,
Given: L = 2r = (2×5) = 10 in, r = 5 in
Substitute these values into equation 2
A' = (10²)-(3.14×5²)
A' = 100-78.5
A = 21.5 in²