SSC CHSL 2023 PYQ — Question 66

SSC CHSL - 09 March 2023 - Shift 4 • Quantitative Aptitude • Q66

The radii of two concentric circles are x cm and 26 cm. P and S are the points on the larger circle, and Q and R are points on the smaller circle. If PQRS is a straight line and QR = 40 cm and PS = 48 cm, then what is the value of x? (x < 26 cm)

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 105\mathbf{\sqrt5} cm.

QR = 40, PS = 48, PO = 26, QO = x

In triangle PTO

PO2 = PT2 + OT2

⇒ 676 = 576 + OT2

OT = 676−576\sqrt{676 - 576} = 10

In triangle QTO

QO2 = QT2 + OT2

x2 = 202 + 102

x = 500\sqrt{500} = 105\mathbf{\sqrt5}