SSC CGL 2021 PYQ — Question 56

SSC CGL - 16 Aug 2021 - Shift 1 • Quantitative Aptitude • Q56

In a circle with center O and radius 5 cm. AB and CD are two parallel chords of lengths 6 cm and x cm, respectively and the chords are on the opposite side of center of the center O. The distance between the chords is 7 cm.

What is the value of x?

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 8

Given :

Radius = 5 cm

AB and CD are two parallel chords

Distance between the chords is 7 cm

AB = 6 cm

CD = x cm

Formula used :

Radius2 = (chord/2)2 + (Length between the chord and centre)2        ---- (1)

Calculations :

Let OM = z

ON = 7 - z

Using equation (1) in ΔOMB\Delta OMB

⇒ 25 = 9 + z2

⇒ 16 = z2

⇒ z = 4 cm

ON = 7 - z 

ON = 3 cm

Using equation (1) in ΔOND\Delta OND

⇒ 25 = 9 + (x/2)2

⇒ 16 = x2/4

⇒ 64 = x2

⇒ x = 8 cm