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XAT 2020 — QA & DI Question 15

2 CirclesEasy

Mohanlal, a prosperous farmer, has a square land of side 2 km. For the current season, he decides to have some fun. He marks two distinct points on one of the diagonals of the land. Using these points as centers, he constructs two circles. Each of these circles falls completely within the land, and touches at least two sides of the land. To his surprise, the radii of both the circles are exactly equal to 2/3 km. Mohanlal plants potatoes on the overlapping portion of these circles.

Answer & solution

  • A

    5( 𝜋 + 4)/27

  • B

    2(2 𝜋 − 3 √3 )/27

  • C

    4(𝜋 − 3 √3 )/27

  • 𝟐(𝝅 − 2)/9

  • E

    (𝝅 − 2)/9

Solution

​​​​​​​

Length of the diagonal AC = 2√2
⇒ AX = ½ of diagonal = √2

Length of AC1 = 2/3 × √2 = 2√2/3

⇒ C1X = AX – AC1 = √2 - 2√2/3 = √2/3

Using Pythagoras theorem:
XM = (23)2-(23)2 = 23

In ∆C1XM,
C1X = XM = √2/3 and ∠C1XM = 90°
⇒ ∠XC1M = 45°

And ∠LC1M = 90°

∴ Area of ∆LC1M = ½ × 2/3 × 2/3 = 2/9

Area of minor arc LM = Area of sector LC1M - Area of ∆LC1M

= 90360×π×(23)2-29 = π-29

∴ Area of overlapping region =  2(π-29)

Hence, option (d).

XAT 2020 QA & DI Q15: Mohanlal, a prosperous farmer, has a square land of side 2 km. For the current season, he decides to have some — Solution | TheCATExam