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
Given:
The measurement of the angles of a triangle are 3b,2b,and 4b.
To find:
The smallest angle.
Solution:
According to the angle sum property, the sum of all angles of a triangle is 180 degrees.
[Angle sum property]
Divide both sides by 9.
Now,
Therefore, the smallest angle is 40 degrees.
Answer: 1:1
Step-by-step explanation:
Let r be the radius and h be the height of a cylinder.
Formula: Curved surface area of cylinder =
Now, if radius of a cylinder is doubled and its height is halved, then new radius will be R= 2r and new height will be
Now, new surface area =
Ratio of curved surface areas :
Hence, the ratios of their surface areas = 1:1 .