A target with a diameter of 70 cm has 4 scoring zones formed by concentric circles. The diameter of the center circle is 10 cm. The width of each ring is 10 cm. A dart hits the target at a random point. Find the probability that it will hit a point in the blue region.

Step-by-step explanation:

see the attached figure to better understand the problem

we know that

The probability that it will hit a point in the blue region  is equal to divide the area of the blue ring by the total area of the target

step 1

Find the area of the blue ring

The radius of the blue ring is

The radius of the red ring is

The area of the blue ring is given by the formula

step 2

Find the total area of the target

The radius of the target  is

 ---> the radius is half the diameter

step 3

Find the probability

Convert to percentage

Multiply by 100

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

(23*2)-12=x     x=34

step-by-step explanation: