#### Question

A target shown in Fig. below consists of three concentric circles of radii, 3, 7 and 9 cm

respectively. A dart is thrown and lands on the target. What is the probability that the dart will land on the shaded region?

#### Solution

1st circle ⟶ with radius 3

2nd circle ⟶ with radius 7

3rd circle ⟶ with radius 9

Area of 1st circle =` (3)^2` = 9𝜋

Area of 2nd circle= `(7)^2` = 49𝜋

Area of 3rd circle = `(9)^2` = 81𝜋

Area of shaded region = Area of 2nd circle – area of 1st circle

= 49𝜋 – 9𝜋

= 40𝜋

Probability that will land on the shaded region =`"area of shaded region"/"area of 3rd circle"`= `(40pi) /(81pi) = 40/81`

Is there an error in this question or solution?

#### APPEARS IN

Solution A Target Shown in Fig. Below Consists of Three Concentric Circles of Radii, 3, 7 and 9 Cm Respectively. a Dart is Thrown and Lands on the Target. What is the Probability that the Dart Will Land on the Shaded Region? Concept: Probability Examples and Solutions.