Since Sylvanite only contains 28% gold by mass, then to obtain 81.0 grams of gold, x amounts of sylvanite must be mined. To determine x, we divide 81 grams by 28%. This equation is shown below:
0.28X = 81
X = 81/0.28
X = 289.29 grams
Therefore, 289.29 grams of sylvanite must be dug up to obtain 81 grams of gold.
The computation shows that the total amount or cost raised will be $250.
<h3>How to calculate the cost?</h3>
From the information given, it was stated that the skating club collected $8 from each of the nine members and had already raised $178.
Therefore, the total amount will be;
= $178 + ($8 × 9)
= $178 + $72
= $250
Therefore, the total amount raised will be $250.
Learn more about cost on:
brainly.com/question/25109150
Using the Fundamental Counting Theorem, it is found that:
The 2 people can arrange themselves in 40 ways.
<h3>What is the Fundamental Counting Theorem?</h3>
It is a theorem that states that if there are n things, each with 
ways to be done, each thing independent of the other, the number of ways they can be done is:
With one people in the aisle and one in the normal seats, the parameters are:
n1 = 4, n2 = 7
With both in the aisle, the parameters is:
n1 = 4, n2 = 3
Hence the number of ways is:
N = 4 x 7 + 4 x 3 = 28 + 12 = 40.
More can be learned about the Fundamental Counting Theorem at brainly.com/question/24314866
#SPJ1
Answer:
sorry bro don't read Spanish but it's not over 3
Step-by-step explanation:
Answer:
none of them
Step-by-step explanation:
Two lines are perpendicular when satisfy the next equation: m1*m2 = -1, where m1 and m2 are the slopes o the lines.
line 1:
y – 1 = (x+2)
y = x + 3
slope of line 1 = 1
line 2:
y + 2 = –3(x – 4)
y + 2 =
-3*x + 12
y = -3*x + 10
slope of line 2 = -3
m1*m2 = 1*(-3
) = -3
They are not perpendicular
line 3:
y − 5 = 3(x + 11)
y − 5 = 3*x + 33
y = 3*x + 38
slope of line 3 = 3
m1*m3 = 1*3 = 3
They are not perpendicular
line 4:
y = -3x –
slope of line 4 = -3
m1*m4 = 1*(-3
) = -3
They are not perpendicular
line 5:
y = x – 2
slope of line 5 = 1
m1*m5 = 1*1 = 1
They are not perpendicular
line 6:
3x + y = 7
y = -3x + 7
slope of line 6 = -3
m1*m6 = 1*(-3
) = -3
They are not perpendicular
