Time, Speed and Distance Questions

Multiple choice
  1. 9 km/hr/किमी./घंटे

  2. 12 km/hr/किमी./घंटे

  3. 10 km/hr/किमी./घंटे

  4. 8 km/hr/किमी./घंटे

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

Downstream speed = 24/2 = 12 km/hr. Upstream speed = 24/4 = 6 km/hr. Speed of boat in still water = (downstream + upstream)/2 = (12 + 6)/2 = 9 km/hr. Option A is correct.

Multiple choice
  1. 24 km./किमी.

  2. 12.5 km./किमी.

  3. 10 km./किमी.

  4. 06 km./किमी.

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

Let distance = d km and scheduled time = t hours. Time at 3 km/hr = d/3, time at 4 km/hr = d/4. Time difference = 20 + 10 = 30 minutes = 0.5 hours. So d/3 - d/4 = 0.5, which gives d/12 = 0.5, therefore d = 6 km.

Multiple choice
  1. 3

  2. 2

  3. 1.5

  4. 1

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

Downstream speed = 9/2 = 4.5 km/hr, upstream speed = 9/6 = 1.5 km/hr. Let boat speed be b and current speed be c. Then b + c = 4.5 and b - c = 1.5. Adding these equations gives 2b = 6, so b = 3 km/hr. This is the speed of the boat in still water.

Multiple choice
  1. 3 km./किमी.

  2. 4 km./किमी.

  3. 3.5 km./किमी.

  4. 2 km./किमी.

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

Time difference between late and early arrival is 6+2=8 minutes. At 5 km/hr and 6 km/hr, let distance=d km. d/5-d/6=8/60 hours. Solving gives d=4 km.

Multiple choice
  1. 200

  2. 300

  3. 350

  4. 400

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

Cars move toward each other at combined speed 30 + 50 = 80 km/h. Time to meet = 800/80 = 10 hours. Distance from first town = 30 × 10 = 300 km. Verification: second car travels 50 × 10 = 500 km, total = 300 + 500 = 800 km. Correct.

Multiple choice
  1. 10

  2. 12

  3. 15

  4. 16

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

Wait, question has error: "swim 3 km/hr in still water" but says "velocity of stream is 2 km/hr". This is contradictory - it says swim speed is 3 km/hr, then says still water speed is 2 km/hr. Assuming swim speed = 3 km/hr (from first statement) and stream = 2 km/hr. Upstream speed = 3 - 2 = 1 km/hr, Downstream = 3 + 2 = 5 km/hr. Time = 10/1 + 10/5 = 10 + 2 = 12 hours.

Multiple choice
  1. 2 kmph/2 किमी प्रति घंटा

  2. 3 kmph/3 किमी प्रति घंटा

  3. 4 kmph/4 किमी प्रति घंटा

  4. 6 kmph/6 किमी प्रति घंटा

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

Total distance = 8 + 6 + 4 = 18 km. Total time = 8/4 + 6/3 + 4/2 = 2 + 2 + 2 = 6 hours. Average speed = 18/6 = 3 km/h. Option A (2 km/h) is arithmetic mean of speeds, which is incorrect for average speed. Option C (4 km/h) is the speed of the first segment only. Option D (6 km/h) is double the correct answer.

Multiple choice
  1. 720

  2. 736

  3. 744

  4. 756

  5. None of these

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

Car speed = 720/9 = 80 km/hr. Bus speed = 3/4 of car = 60 km/hr. Given bus:train = 15:27, so train speed = 60 × 27/15 = 108 km/hr. Distance by train in 7 hours = 108 × 7 = 756 km.

Multiple choice
  1. 6.5 km/hr

  2. 6 km/hr.

  3. 5 km/hr.

  4. 5.5 km/hr.

  5. 4 km/hr.

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

Against stream: speed = 40/8 = 5 km/hr (boat - stream). With stream: speed = 36/6 = 6 km/hr (boat + stream). Adding: 2 × boat = 11, so boat = 5.5 km/hr. Option B (6 km/hr) is the downstream speed, not still water speed.

Multiple choice
  1. $50 km/hr.$
  2. $60 km/hr.$
  3. $70 km/hr.$
  4. $75 km/hr.$
  5. $80 km/hr.$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let speed of B = v km/hr, speed of A = u km/hr. Distance = 600 km. Time A = 600/u, Time B = 600/v. First condition: 600/u = 600/v + 6. When A's speed doubles: 600/(2u) = 600/v - 2. Solving gives v = 60 km/hr. From equation: 600/v = 600/u - 6. Substituting v = 60: 10 = 600/u - 6, so u = 37.5. Verify: 600/37.5 = 16 hrs, 600/60 = 10 hrs. Difference is 6 hours ✓ When A doubles: 600/75 = 8 hrs, which is 2 hrs less than B ✓

Multiple choice
  1. 2 km/hr.

  2. 3 km/hr.

  3. 4 km/hr.

  4. 4.5 km/hr.

  5. 5 km/hr.

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

Total distance = 18 km covered in 3 hours downstream + 3 hours upstream. Speed = distance/time = 18/6 = 3 km/hr. This average speed equals the speed in still water since the time spent going upstream and downstream is equal.

Multiple choice
  1. 40 km/hr

  2. 12 km/hr

  3. 7.5 km/hr

  4. 5 km/hr

  5. 2.5 km/hr

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

Downstream speed = 1440/36 = 40 km/hr. Boat speed + stream speed = 40. Given stream = boat/7, let boat = 7x, stream = x. 7x + x = 40, so 8x = 40, x = 5. Stream speed is 5 km/hr. Option D matches.

Multiple choice
  1. 60 km./hr./किमी./घं.

  2. 65 km./hr./किमी./घं.

  3. 70 km./hr./किमी./घं.

  4. 75 km./hr./किमी./घं.

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

When distances are equal, average speed = 2ab/(a+b) where a and b are the two speeds. Here: 2×60×100/(60+100) = 12000/160 = 75 km/hr. The average is always less than the arithmetic mean (80) because more time is spent at the slower speed.