40 boys and 68 girls
let's start with variables and an equation.
boys: x
girls: 2x - 12
and we know that boys and girls make up the class. so let's add the two expressions.
x + 2x - 12 = 108
3x - 12 = 108
+ 12 + 12
3x = 120
x = 40 boys
BUT x is only the number of BOYS in the class. so we have to find girls now. let's plug in our value of x into the girls' equation.
2x - 12 = # of girls
2(40) -12 = # of girls
80 - 12 = # of girls
68 girls
let's check our answer!
68 + 40 does in fact add to 108, therefore our answer is correct.
c. 4.6
21 X .22= 4.6
Calculating the variance requires finding the product of 21 and 22%. To make this easier we convert 22% into it's decimal form and construct the equation. To back check this answer we can use 10% of 21 voters which equals 2.1% then double that amount to reach 4.2%, knowing that we now have a close approximation of the variance we can eliminate answers a, b, and d, leaving c as the only logical choice.
To find the volume of a dome, you would have to find the volume of the sphere, theoretically, and then divide it by two. To calculate the volume, we would use the formula 4/3
. The radius (r) in this case is half of the diameter which is 14. 4 x 3.14 (pi) = 12.56. 12.56 x 14 x 14 x 14 (2744) = 34464.64. If we divide this number by 3, we get 11488.2133. If we divide this by 2 (to get the dome), we get 5744.10656. Which would be 5744.1 rounded to the nearest tenth.
The answer to your question is B!
Have a wonderful day.
Answer:
3 x 4 = 12
4 x 5 = 20
5 x 2 = 10
Step-by-step explanation:
3 + 3 + 3 + 3 = 12
3 four times equals 12
This is the same for the others
4 + 4 + 4 + 4 + 4 = 20
Four 5 times equals 20
