Answer:
<em>There are 12 boys and 18 girls</em>
Step-by-step explanation:
<u>Equations</u>
There are 30 students in a class. Let's call:
x = number of boys
Since the sum of boys and girls is 30:
30 - x = number of girls
The ratio of boys to girls is 2:3, thus:
Crossing denominators:
3x = 2(30 - x)
Operating the parentheses:
3x = 60 - 2x
Adding 2x:
5x = 60
Dividing by 5:
x = 60/5 = 12
x = 12
There are 12 boys and 30-12=18 girls
No she not correct. 80% of the students are wearing tennis shoes
Answer:
80%
Step-by-step explanation:
To find percentage increase, we use the following formula:
Percentage Increase = 
Here
New means the latest value (which is 18 dancers)
Old means the previous value (which is 10 dancers)
The Multiplication by 100 is to convert the decimal answer to percentage.
So, we have:
New = 18
Old = 10
Now we substitute and find:
So, there was an increase of 80%
20 with a number minus what will equal 9. ^_^
