Remember you can do anything to an equation as long as you do it to both sides
x+9=18-2x
add 2x to both sides
2x+x+9=18+2x-2x
3x+9=18+0
3x+9=18
minus 9 both sides
3x+9-9=18-9
3x+0=9
3x=9
divide both sides by 3
(3x)/3=9/3
(3/3)x=3
1x=3
x=3
There are 600 students including the seventh and eighth graders at the party.
This problem uses the concept of percentages to define the conditions that are laid in front of us.
Let the original number of students be S , and the number of seventh graders be = 0.60S
We know that percent is used to convey the mathematical term of a fraction multiplied by 100.
Total students after 20 eighth graders arrive = S + 20
And we have that
Number of seventh graders / total number of students = 58%
.60S / [ S + 20 ] = .58 we multiply both sides by S + 20
0.60S =0 .58 [ S + 20]
.60S = .58S + 11.6 we subtract 0.58S from both the sides
0.02S = 11.6 we divide both the sides by .02
S = 11/6 / 0.02 = 580
So the total number of students = 580 + 20 = 600 .
Hence there are 600 students at the party at that time.
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Answer:
61.5%
Step-by-step explanation:
Let's find all the demographics first:
Sophomores in the class(total 15):
Female: 5
Male : 10
Freshmen in the class(total 11):
Female: 3
Male: 8
There are 11 freshmen(male and female) and 5 female sophomores. Thus, the probability of choosing one of these 16 people in a class of 26 is 16/26 or 61.5%.
The equation that would best describe the situation would be the first option. To solve this question, simply break down the question into sections and then use variables X and y to represent each of the things asked for in the problem. We know the following:
X = no of tetra fish
Y = no of goldfish
If there is twice as much goldfish than tetra fish, then it would be 2y.
X = 2Y.
Then knowing what X and y represent, find the equation that gives the total cost of fish he bought, knowing that 1.50 is for a goldfish and 2.00 is for a tetra fish.
