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

answer: 12

step-by-step explanation:

-362

step-by-step explanation:

(12)(4)+2(12)-34(12)+2(12)-3

  \/         \/         \/         \/

  48 +   24 -   408 + 24 - 3

      \   /               \   /

          72     -     432 - 3 = -363