# Practice Clocks - verbal reasoning Online Quiz (set-1) For All Competitive Exams

#### Q-1) How many rotations will the hour hand of a clock complete in 72 hours?

(a)

(b)

(c)

(d)

**Explanation:**

Number of rotations = $72/12$ = 6

#### Q-2) How many times are the hour hand and the minute hand of a clock at right angles during their motion from 1.00 p.m. to 10.00 p.m.?

(a)

(b)

(c)

(d)

(e)

**Explanation:**

The duration from 1.00 p.m. to 10.00 p.m. is 9 hours and during each of these 9 hours the hands of a clock are at right angles twice.

So, required number = 9 × 2 = 18.

#### Q-3) How many times in 24 h the hands of a clock are in straight line but opposition in directions?

(a)

(b)

(c)

(d)

**Explanation:**

The hands of a clock are in the same straight line (but opposite in direction) 11 times in every 12 h, because between 5 and 7 they point in opposite direction at 6 O' clock only.

Therefore, in a day (24 h) the hands points in the opposite direction (2 × 11) = 22 times.

#### Q-4) How many times the hand of a clock are at right angle in a day?

(a)

(b)

(c)

(d)

**Explanation:**

We know that the hands of a clock are at right angle twice in every hour but between 2 and 4 O' clock there is a common position at 3 O' clock and also between 8 and 10 O' clock there is common position at 9 O' clock.

So, they are at right angles 22 times in 12 h and therefore, in 24 h or in a day they are at right angle 44 times.

#### Q-5) How many times in a day, are the hands of a clock in straight line but opposite in directions?

(a)

(b)

(c)

(d)

**Explanation:**

The hands of a clock point in opposite directions (in the same straight line) 11 times in every 12 hours (Because between 5 and 7 they point in opposite directions at 6 O' clock only).

So, in a day, the hands point in the opposite directions 22 times.

#### Q-6) Find the angle between the hands of clock at 8 : 20.

(a)

(b)

(c)

(d)

**Explanation:**

∴ Angle traced by hour hand per minute =$(1/2)^o$

∴Angle traced by hour hand in 8h 20 min = ( 8 x 60 + 20) ×$ 1/2$ = 205°

Again, angle traced by minute hand per minute = 6°

∴ again traced by minute hand in 20 min = 20 × 6°

= 120°

Therefore required angle = (250° - 120°) = 130°

#### Q-7) What will be the angle between the hands of clock at 7 : 10?

(a)

(b)

(c)

(d)

**Explanation:**

∴ angle traced by hour hand per minute = $(1/2)^o$

∴ angled traced by hour hand in 8 h 30 min =$[{(8 × 60) + 30}x1/2]^o$

= $[{480 + 30} ×1/2]^o$ = 510 × $(1/2)^o$ = 255°

∴ Angle traced by minute hand per minute = 6°

∴ Angle traced by minute hand in 30 min = 30 × 6° = 180°

∴ required angle = (255° - 180°) = 75°

#### Q-8) Find the angle traced by hour hand of a correct clock between 8 O' clock and 2O' clock.

(a)

(b)

(c)

(d)

**Explanation:**

∴ Angle traced by hour hand per minute = $(1/2)^o$

∴ Angle traced by hour hand in 1 h = 1°/2 × 60 = 30°

Time period between 8 O' clock to 2 O' clock = 6h

∴ angle traced by hour hand in 6h = 30° × 6 = 180°

#### Q-9) Imagine that your watch was correct at noon, but then it began to lose 30 minutes each hour. It now shows 4 p.m. but it stopped 5 hours ago. What is the correct time now?

(a)

(b)

(c)

(d)

**Explanation:**

The watch loses 1/2 hour each hour.

So, it must have taken 8 hours to show 4 p.m. from 12 noon.

Thus, it stopped at 8 p.m. So, the correct time is 5 hours ahead of 8 p.m., i.e., 1 a.m.

#### Q-10) A watch goes fast by 15 minutes compared to the right time everyday. If it is corrected and set to the standard time at 120' clock at noon, which of the following will be the time shown by it at 4:00 a.m. in the morning?

(a)

(b)

(c)

(d)

**Explanation:**

Duration from 12 noon to 4:00 a.m. = 16 hours.

Time gained in 24 hours = 15 min.

Time gained in 16 hours = (5/24 × 16) min = 10 min.

#### Q-11) Through what angle does the minute hand of a clock turn in 5 minutes?

(a)

(b)

(c)

(d)

**Explanation:**

Angle traced by the minute hand in 5 minutes = $(360/60 × 5)^o = 30°$

#### Q-12) A clock, which loses uniformly, is 15 min fast at 9 am on 3rd of the December and is 25 min less than the correct time at 3 pm on 6th of the same month. At what time it was correct?

(a)

(b)

(c)

(d)

**Explanation:**

Time of the last train leaving the station = (18 : 00 - 2 : 30)h = 15 : 30h

But this happens 40 min before the announcement is made.

Hence, Time of making announcement = (15 : 30 + 0 : 40) = 16 : 10h

#### Q-13) A clock gains 5 minutes in one hour. Therefore, the angle traversed by the minute hand in 1 hour is

(a)

(b)

(c)

(d)

**Explanation:**

Clearly, the minute hand traverses 65 minutes in 1 hour.

∴ Required angle = $(360/60 × 65)^o = 360°$

#### Q-14) An accurate clock shows 8O' clock in the morning. Through how many degrees will the hour hand rotate when the clock shows 2O, clock in the afternoon?

(a)

(b)

(c)

(d)

**Explanation:**

Angle traced by the hour hand in $6 hours = (360/12 × 6)^o$ = 180°

#### Q-15) How much angular distance will be covered by the minute hand of a correct clock in a period of 2 h 20 min?

(a)

(b)

(c)

(d)

**Explanation:**

Angle traced by minute hand per minute = 6°

Therefore angle traced by minute hand in 12 h 20 min = [(2 × 60) + 20] × 6°

= (120 + 20) × 6° = 140 × 6° = 840°

#### Q-16) There are 20 people working in an office. The first group of five works between 8 am and 2 pm. The second group of ten works between 10 am and 4 pm and the third group of five works between 12 noon and 6 pm. There are three computers in the office which all the employees frequently use. During which of the following hours, the computers are likely to be used the most?

(a)

(b)

(c)

(d)

**Explanation:**

It is obvious that computers would be used most when all the three groups are working simultaneously and this happens during the period 12 noon to 2 pm.

#### Q-17) **Match List I with List II and select the correct answer using the codes given below the lists:**

List I (Time) | List II (Angle between hour hand and minute hand of a clock) |

A. 1:10 PM | 20° |

B. 2:15 PM | 22$1/2$° |

C. 8:40 PM | 24° |

25° | |

30° |

(a)

(b)

(c)

(d)

**Explanation:**

(A) Angle traced by hour hand in$ 7/6 hrs = (360/12 × 7/6)^o = 35°$

Angle traced by minute hand in $10 min = (360/60 × 10)^o = 60°$

∴ Required angle = (60° - 35°) = 25°

(B) Angle traced by hour hand in $9/4 hrs = (360/12 × 9/4)^o = 67 1°/2$

Angle traced by minute hand in $15 min = (360/60 × 15)^o = 90°$

∴ Required angle = $(90° - 67 1°/2) = 22 1°/2$

(C) Angle traced by hour hand in $26/3 hrs = (360/12 × 26/3)^o = 260°$

Angle traced by minute hand in $40 min = (360/60 × 40)^o$ = 240°

∴ Required angle = (260° - 240°) = 20°

#### Q-18) At what time between 4 and 5 O' clock will the hands of a clock be at right angle?

(a)

(b)

(c)

(d)

**Explanation:**

Between 4 and 5 O' clock the hands of the clock will be at right angle twice, first situation will occur when minute hand is 15 min spaces behind the hour hand and the second when minute hand is 15 min spaces ahead of the hour hand.

Fig. (ii) shows the position when minute hand is 15 min spaces behind the hour hand. To come at this position, minute hand has to gain 5 min spaces from the position at 4 O' clock. Now, 55 min are gained by minute hand in 60 min. Therefore, 5 will be gained in$ 60/55 × 5 = 60/11 $min It means that hands of the clock will be at right angle at 5$ 5/11$ min past 5.

Fig, (iii) shows the position when minute hand is 15 min spaces ahead the hour hand. To come at this position, minute hand has to gain 35 min spaces from the position at 4 O' clock Now, 55 min are gained in 60 min.

Therefore, 35 min spaces will be gained in 60 min = $60/55 × 35 min = 420/11$ min It means that second position will come at $38 2/11$ min past 4.

Now, in options 38$ 2/11 $min past 4 is available as option (c).

#### Q-19) At what time between 5 and 6 are the hands of a clock coincident?

(a)

(b)

(c)

(d)

**Explanation:**

From the figure, we find that min hand is 25 min spaces behind the hour hand. In order to coincide, it has to again 25 min spaces.

Now, 55 min are gained by minute hand in 60 min.

Therefore, 25 min will be gained in $60/55 × 25 = 27 3/11$

So, the hands will coincide at 27 $3/11$ min past 5.

#### Q-20) At what time between 3 and 4 O' clock will the hands of a clock coincide?

(a)

(b)

(c)

(d)

**Explanation:**

At 3 O' clock both the hands of the clock are 15 min apart. Hence, in order to be together, minute hand will have to gain 15 min spaces in order to coincide with the hour hand. Now, 55 min are gained by minute hand in 60 min.

Therefore, 15 min will be gained in $(60/55 × 15) min = (12/11 × 15) min $= $180/11 or 16 4/11 min$

Therefore, the hands will coincide at 16$ 4/11$ min past 3.