The minute hand of a clock is 20 cm long. Find the area on the face of the clock swept by the minute hand between 8 a.m. and 8:45 a.m.

Question

Question

This question was previously asked in

SSC CGL 2022 Tier-I Official Paper (Held On : 12 Dec 2022 Shift 1)

Answer 1

Given:

The minute hand of a clock is 20 cm long.

Concept used:

Area of a sector = πr² × \({{\theta} \over 360}\)

Calculation:

As we know in the 1-minute angle made by the minute hand = 6°

So, in 45 min the minute hand will make 45 × 6 = 270°

Area = π × 20² × \({{270} \over 360}\)

⇒ \({{22} \over 7}\) × 400 × \({{270} \over 360}\)

⇒ \({{6600} \over 7}\)

∴ The required answer is \({{6600} \over 7}\) cm2