Time, Speed and Distance Questions

Multiple choice
  1. 4480 km

  2. 4000 km

  3. 3600 km

  4. 4500 km

  5. 5480 km

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

Let total distance be D. Time for first half = (D/2) / 210 = D/420. Time for second half = (D/2) / 240 = D/480. Total time = D/420 + D/480 = 20. D(8+7)/3360 = 20 => 15D/3360 = 20 => D = (20*3360)/15 = 4480.

Multiple choice
  1. 10 miles

  2. 18 miles

  3. 20 miles

  4. 25 miles

  5. 35 miles

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

Let the car speed be v. The dog's speed is 2v. The car has a 9-mile head start. Time for dog to catch car = (Head start distance) / (Relative speed) = 9 / (2v - v) = 9/v. Distance covered by dog = Speed * Time = 2v * (9/v) = 18 miles.

Multiple choice
  1. 4 : 8 : 3

  2. 3 : 8 : 4

  3. 8 : 4 : 3

  4. 8 : 3 : 4

  5. 4 : 3 : 8

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

Since speed is inversely proportional to time for a constant distance, the ratio of time taken is the inverse of the ratio of speeds. The inverse of 3:6:8 is 1/3 : 1/6 : 1/8. Multiplying by the least common multiple (24) gives 8 : 4 : 3.

Multiple choice
  1. 48 kmph

  2. 50 kmph

  3. 52.5 kmph

  4. Cannot be determined

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

Let D be the distance. Time at 40 km/hr is D/40. Time at 60 km/hr is D/60. The difference is 2 hours: D/40 - D/60 = 2. D/120 = 2, so D = 240 km. To reach 1 hour early (compared to 40 km/hr), he needs to take (D/40 - 1) hours. Time = 6 - 1 = 5 hours. Speed = 240 / 5 = 48 km/hr.

Multiple choice
  1. 45 km/hr

  2. 50 km/hr

  3. 52.5 km/hr

  4. 48 km/hr

  5. None of these

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

Average speed = Total distance / Total time. Let total distance be 3D. Time = (2D/40) + (D/60) = D/20 + D/60 = 4D/60 = D/15. Average speed = 3D / (D/15) = 45 km/hr.

Multiple choice
  1. 8

  2. 9

  3. 10

  4. 11

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

Let speeds be v and v+7. Relative speed = 2v+7. Distance = 138, time = 6. 6(2v+7) = 138. 2v+7 = 23. 2v = 16, v = 8.

Multiple choice
  1. 35

  2. 40

  3. 45

  4. 50

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

Average speed = Total distance / Total time. Let distance between cities be D. Time 1 = D/60, Time 2 = D/40, Time 3 = D/120, Time 4 = D/20. Total time = D(1/60 + 1/40 + 1/120 + 1/20) = D(2/120 + 3/120 + 1/120 + 6/120) = 12D/120 = D/10. Total distance = 4D. Average speed = 4D / (D/10) = 40 kmph.

Multiple choice
  1. Only I

  2. Only II and III

  3. Only I and II

  4. Any two of the given three

  5. All three statements together cannot give the answer.

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

Let u be speed upstream and v be speed downstream. Statement I gives u = 15/3 = 5 km/hr. Statement II gives v = 30/2 = 15 km/hr. Still water speed = (v+u)/2 = (15+5)/2 = 10 km/hr. Statement III also allows finding u and v. Any two statements are sufficient.

Multiple choice
  1. 30 min

  2. 1 h

  3. 1 h 12 min

  4. 1 h 15 min

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

Let the speeds be v1, v2, v3. We have v2 = v1 - 15 and v2 = v3 + 3. Using time = distance/speed and the time differences (12 min = 0.2 h, 6 min = 0.1 h), we set up equations for the distance D: D/v2 - D/v1 = 0.2 and D/v3 - D/v2 = 0.1. Solving these yields the time taken by the third motorbike.

Multiple choice
  1. 40, 30

  2. 40, 50

  3. 60, 30

  4. 50, 60

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

Let speeds be x and y. Opposite: (x+y) = 90 / (9/7) = 70. Same direction: (x-y) = 90 / 9 = 10. Adding: 2x = 80 -> x = 40. Subtracting: 2y = 60 -> y = 30.

Multiple choice
  1. 1

  2. 3

  3. 4

  4. 2

Reveal answer Fill a bubble to check yourself
B Correct answer