Given that there were 30 bacteria present originally.
a=30
Also given that the number doubles every one hour.
After one hour the count =2×30=60
Since the count doubles every hour it forms a G.P. with r=2
a,ar,ar2........
The count at the end of 2nd hour=ar^2=30×2^2=120
The count at the end of 4th hour=ar^4=30×2^4=480
The count at the end of 8th hour=ar^8n=30×2^8=7680
etc.
The count at the end of n^th hour=ar^n=30×2^n
Also, the equation y=30*(2)^8/1 give the same result y= 7680
        
             
        
        
        
To answer question 12, you first need to know the definition of a <em>prism</em> and a<em> pyramid.
</em>A <em>pyramid </em> is a 3-D structure with one base, whose outer faces are made of triangles, and meet at a single point at the top.
A <em>prism</em> is any 3-D shape with a base of any number of sides, another base with the same amount of sides, and faces joining the two together on every side of the bases.
12. 
Shape A is a <em>pyramid</em>, because it has one base, and all the faces join together in at one point.
Shape B is a <em>prism</em>, because it has two bases, and faces joining every side of the bases. 
Shape C is a <em>prism.</em>
Shape D is a <em>pyramid.
</em>For #13, you have to know the definition of a cube to figure out the math of how many cubes there are. 
A cube is a 3-D shape with six sides, all made up of squares of the same size. 
The box has a volume of 120 cubic inches, and each cube is 1 inch. Since every side of a cube is equal, a 1-inch cube is one cubic inch. 
This means that a box with a volume of 120 cubic inches will fit 120 of the 1 inch cubes.
1 layer of the cubes, in the diagram, is 8 cubes by 3 cubes, or 24 cubes total. 
To find the number of layers needed to fill the box, you divide 120 by 24.
120 ÷ 24 = 5
The answer to #13 is 5 layers.
        
             
        
        
        
Answer:
1. is 25%
Step-by-step explanation:
3.00 - 0.6 = 2.4
 
        
             
        
        
        
Answer:
7 green cars.
Step-by-step explanation:
Look at the totals of all of the colors at the bottom. The least of them is green (at 7 cars). That's the answer.
 
        
             
        
        
        
Answer:
D) 3.28
Step-by-step explanation:
820/x=100/2.5
(820/x)*x=(100/2.5)*x       - we multiply both sides of the equation by x
820=40*x       - we divide both sides of the equation by (40) to get x
820/40=x
20.5=x
x=20.5
now we have:
2.5% of 820=20.5