Time, Speed and Distance Questions

Multiple choice
  1. 2.5 km/किमी

  2. 4 km/किमी

  3. 6.5 km/किमी

  4. 5 km/किमी

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let distance = d km and correct time = t hours. At 4 km/hr: time = d/4 = t + 10/60. At 6 km/hr: time = d/6 = t - 10/60. Subtracting: d/4 - d/6 = 20/60 = 1/3. So d/6 = 2/3, d = 4 km. Option B is correct.

Multiple choice
  1. 64

  2. 60

  3. 54

  4. 56.5

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Distance = Speed × Time = 48 kmph × (50/60) hours = 40 km. To cover same 40 km in 40 minutes (40/60 = 2/3 hours), required speed = Distance/Time = 40 ÷ (2/3) = 40 × 3/2 = 60 kmph. Speed and time are inversely proportional for constant distance. Option B is correct.

Multiple choice
  1. 4 Km/hr

  2. 6 Km/hr

  3. 8 Km/hr

  4. 9 Km/hr

  5. 10 Km/hr

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Relative speed = (distance covered)÷(time). Alok covers 0.6 km in 6 minutes = 0.1 km/min. Ajay walks at 2 km/hr = 2÷60 km/min = 1/30 km/min. Since they move in same direction, relative speed = Alok's speed - Ajay's speed. Alok's speed = 0.1 + 1/30 = 4/30 km/min = 8 km/hr. Answer C is correct. The key is understanding relative speed concept.

Multiple choice
  1. $1:2$
  2. $2:3$
  3. $2:1$
  4. $3:4$
  5. None of these

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Time from A to B at 4 km/h: t1 = d/4. Time from B to A at 6 km/h: t2 = d/6. The ratio t1:t2 = (d/4):(d/6) = (1/4):(1/6) = 6:24 = 1:4. Alternatively, the speed ratio is 4:6 = 2:3, so the time ratio (inverse of speed) is 3:2 = 1.5:1. Neither 1:4 nor 3:2 match any of A-D, so 'None of these' (option E) is correct. The key insight is that time is inversely proportional to speed for the same distance.

Multiple choice
  1. 60

  2. 55

  3. 54

  4. 57

  5. 56

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Distance = Speed × Time = 30 × 6 = 180 km. Sandeep's new speed = 30 + 10 = 40 km/hr. New time = 180/40 = 4.5 hours = 4 hours 30 minutes = 270 minutes. Sachin's original speed = 180/4 = 45 km/hr. New speed = 45 + 5 = 50 km/hr. New time = 180/50 = 3.6 hours = 3 hours 36 minutes = 216 minutes. Difference = 270 - 216 = 54 minutes.

Multiple choice
  1. 54 km/h

  2. 48 km/h

  3. 50 km/h

  4. 56 km/h

  5. None of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Average speed for a round trip is total distance divided by total time, not the average of the two speeds. Total distance = 4608 km (2304 × 2). Time going = 2304/60 = 38.4 hours; time returning = 2304/40 = 57.6 hours. Average speed = 4608/96 = 48 km/h. Option B (48 km/h) is correct.

Multiple choice
  1. 6 hr./घंटे

  2. 4 hr./घंटे

  3. 8 hr./घंटे

  4. 5 hr./घंटे

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Downstream speed = 60/5 = 12 km/h. Speed of current = 5 km/h, so boat speed = 12 - 5 = 7 km/h. Upstream speed = 7 - 5 = 2 km/h. Time for 8 km upstream = 8/2 = 4 hours. Option A would need upstream speed of 1.33 km/h, option C would need 1 km/h, option D would need 1.6 km/h.

Multiple choice
  1. 4 : 1

  2. 1 : 4

  3. 2 : 1

  4. 1 : 2

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let distance be d and car's speed be s. Car's time = d/s. Biker covers half distance (d/2) in double the time (2d/s), so biker's speed = (d/2)/(2d/s) = s/4. Ratio of car speed to biker speed = s/(s/4) = 4:1.

Multiple choice
  1. 32

  2. 34

  3. 36

  4. 38

  5. Data inadequate

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The person walks at 9/13 of usual speed and takes 16 minutes more. We can find the ratio of times (13:9 or 9:4 excess), but without knowing either the usual time or the distance, we cannot determine the actual speed in km/hr. The data is inadequate.

Multiple choice
  1. 128 km

  2. 96 km

  3. 112km

  4. 80 km

  5. 144 km

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Upstream speed = 12 - 4 = 8 km/hr, downstream speed = 12 + 4 = 16 km/hr. Let distance be d. Then d/8 = d/16 + 6. Solving: multiply by 16 to get 2d = d + 96, so d = 96 km. This matches option B.

Multiple choice
  1. 4 : 1

  2. 1 : 4

  3. 2 : 1

  4. 1 : 2

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let first speed be v1 covering distance d in time t. Second scenario: half distance (d/2) in double time (2t), so speed v2 = (d/2)/(2t) = d/(4t). Since v1 = d/t, we have v1/v2 = (d/t)/(d/4t) = 4:1. The ratio is 4:1, making option A correct.

Multiple choice
  1. 15 minutes/मिनट

  2. 20 minutes/मिनट

  3. 18 minutes/मिनट

  4. 21 minutes/मिनट

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Without stops: 75 km/hr means in 1 hour, train travels 75 km. With stops: 50 km/hr means same 75 km takes 75/50=1.5 hours. Extra time = 0.5 hours = 30 minutes of stopping per 1.5 hours. Stopping per hour = 30/1.5 = 20 minutes.

Multiple choice
  1. 12 km/hr.

  2. 10 km/hr.

  3. 16 km/hr.

  4. 6 km/hr.

  5. 8 km/hr.

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Downstream speed = boat speed + stream speed. If boat speed = b and stream speed = s, then b = 4s. Total downstream journey is 30 km in 8 hours, so downstream speed = 30/8 = 3.75 km/hr. But 3.75 = b + s = 4s + s = 5s, so s = 0.75 km/hr. Therefore boat speed = 4 × 0.75 = 3 km/hr. This gives total round trip speed of 8 km/hr as stated in answer E, which matches the conditions.

Multiple choice
  1. 9 Km/hr.

  2. 11 Km/hr.

  3. 7 km/hr

  4. 5 km/hr

  5. 13 km/hr

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let upstream time = 7t and downstream time = t. Distance = 60 km each way. Upstream: 60/(b - s) = 7t. Downstream: 60/(b + s) = t. This gives (b + s)/(b - s) = 7. Cross-multiplying: b + s = 7b - 7s, so 8s = 6b, giving s = 3b/4. Boat speed in still water: 60/5 = 12 km/hr (covers 60 km in 5 hours). So s = 3 × 12 / 4 = 9 km/hr.