Solution

Given:• In the given figure, the circular clock shows a time of exactly 3:30

To find:• The value of x

Approach and Working:Method 1: Taking the reference time as 12:00 hrs• If we consider the movement of the minute hand and hour hand separately, with respect to 12:00 hrs, we can calculate their individual displacement

• The minute hand of a clock covers a distance of 360° in 60 minutes

o Hence, it covers a distance of 6° in every minute

• The hour hand covers a distance of 360° in 12 hrs = 720 minutes

o Hence, it covers a distance of \(\frac{1}{2}\)° in every minute

Now, after the completion of every hour, minute hand comes to 12.

• Hence, at 3:30, the movement of the minute hand = 30 * 6° = 180°

From 12:00 hrs to 3:30, the hour hand moves for a time of 3.5 hrs = 210 minutes

• Hence, at 3:30, the movement of the hour hand = 210 * \(\frac{1}{2}\)° = 105°

• Therefore, the distance in between the minute and the hour hand = x = 180° - 105° = 75°

Method 2: Taking the reference time as 3:00 hrsAt 3:00 hrs, the minute hand will be at 12 and the hour hand will point towards 3, making a gap of 90° in between

• At 3:30 hrs, the minute hand will make a movement from 12 to exact opposite at 6, hence covering a distance of \(\frac{360°}{2}\) = 180°

o Hence, from 3, the displacement of minute hand = 180° - 90° = 90°

• At 3:30 hrs, the hour hand will move exactly in between 3 and 4, covering a distance of \(\frac{1}{2}\) * \(\frac{360°}{12}\) = 15°

• Therefore, the distance between the minute and the hour hand = x = 180° - 105° = 75°

Hence, the correct answer is option B.

Answer: B
_________________

Register for free sessions

Number Properties | Algebra |Quant Workshop

Success Stories

Guillermo's Success Story | Carrie's Success Story

Ace GMAT quant

Articles and Question to reach Q51 | Question of the week

Must Read Articles

Number Properties – Even Odd | LCM GCD | Statistics-1 | Statistics-2 | Remainders-1 | Remainders-2

Word Problems – Percentage 1 | Percentage 2 | Time and Work 1 | Time and Work 2 | Time, Speed and Distance 1 | Time, Speed and Distance 2

Advanced Topics- Permutation and Combination 1 | Permutation and Combination 2 | Permutation and Combination 3 | Probability

Geometry- Triangles 1 | Triangles 2 | Triangles 3 | Common Mistakes in Geometry

Algebra- Wavy line | Inequalities

Practice Questions

Number Properties 1 | Number Properties 2 | Algebra 1 | Geometry | Prime Numbers | Absolute value equations | Sets

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com