Answer:
85, 68, 51
Step-by-step explanation:
Average: The sum of all the numbers divided by the number of numbers
If the ratio of the scores is 5 : 4 : 3, let's just set it as 5x : 4x : 3x
Then using the definition of an average, we can write this equation.
(5x + 4x + 3x) / 3 = 68
Multiply both sides by 3.
5x + 4x + 3x = 68 * 3
Simplify.
12x = 204
x = 17
Now, substitute x = 17 into the original scores (5x, 4x, and 3x)
5x = 5 * 17 = 85
4x = 4 * 17 = 68
3x = 3 * 17 = 51
Just in case, let's check this answer. Find the average of the 3 test scores.
(85 + 68 + 51) / 3 =
204 / 3 = 68
Thus, the answers are correct
It has no solution
18m+7=18m+7
Which means they are the same equation !!
Answer:
20 square units
Step-by-step explanation:
count the face of the figure one by one
<span>Dr. Graham currently has two acid solutions.
60% acid AND 20% acid </span>
Dr. Graham needs 30 L of a 50% acid solution
We set up 2 equations in which s = 60% acid and t = 20% acid
A) s + t = 30
B) .60s + .20t = (.50 * 30)
We multiply equation A by -.20
A) = -.20s -.20t = -6 then we add it to B)
B) .60s + .20t = 15
.40s = 9
s = 22.5
t = 7.5
So, she needs to mix 22.5 liters of 60% acid with 7.5 liters of 20% acid.
Source:
http://1728.org/mixture.htm
