Time, Speed and Distance Questions

Multiple choice
  1. 54 km/hr

  2. 62.86 km/h

  3. 52.38 km/hr

  4. 104.76 km/hr

  5. 60 km/hr

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

Total time is 37 hours, minus 2 hours halt = 35 hours travel time. Let v be the onward speed; return speed is 1.2v. Distance is 1000 km each way. Equation: 1000/v + 1000/(1.2v) = 35. Solving for v gives v = 52.38 km/hr. Return speed = 1.2 * 52.38 = 62.86 km/hr.

Multiple choice
  1. 2400 km

  2. 2550 km

  3. 2700 km

  4. 2800 km

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

Let time be t. Distances are 70t and 90t. 90t - 70t = 350 => 20t = 350 => t = 17.5 hours. Total distance = 70t + 90t = 160t = 160 * 17.5 = 2800 km.

Multiple choice
  1. 92.5 min

  2. 88.5 min

  3. 84.5 min

  4. 60.5 min

  5. 45 min

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

Hare speed = 24 km/hr = 400 m/min. Tortoise speed = 0.4 km/hr = 400/60 = 6.67 m/min. Tortoise time = 600 / 6.67 = 90 min. Hare running time = 600 / 400 = 1.5 min. Sleep time = 90 - 1.5 = 88.5 min.

Multiple choice
  1. 5 km

  2. 6 km

  3. 10 km

  4. 5.25 km

  5. 15 km

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

Let distance be D. Time at 15 km/hr is D/15, time at 20 km/hr is D/20. The difference in time is 3 minutes late + 2 minutes early = 5 minutes = 5/60 hours. So, D/15 - D/20 = 5/60. (4D - 3D)/60 = 5/60, which gives D = 5 km.

Multiple choice
  1. 12 km/hr

  2. 10 km/hr

  3. 8 km/hr

  4. 6 km/hr

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

Let Ajay's speed be v. Ravi's speed is v-4. Ajay travels 60 km to B and then 12 km back, total 72 km. Ravi travels 60-12 = 48 km. Since they start and meet at the same time, 72/v = 48/(v-4). Solving this gives 72(v-4) = 48v, 72v - 288 = 48v, 24v = 288, v = 12. Ravi's speed is 12-4 = 8 km/hr.

Multiple choice
  1. 33 : 13

  2. 23 : 13

  3. 13 : 23

  4. 33 : 12

  5. None of these

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

Upstream time = 6h 54m = 6.9h. Downstream time = 3h. Let distance be D. Upstream speed (u-v) = D/6.9. Downstream speed (u+v) = D/3. u = (D/3 + D/6.9)/2 = D(1/6 + 1/13.8) = D(2.3+1)/13.8 = 3.3D/13.8. v = (D/3 - D/6.9)/2 = D(2.3-1)/13.8 = 1.3D/13.8. Ratio u:v = 3.3:1.3 = 33:13.

Multiple choice
  1. 36 metres

  2. 48 metres

  3. 60 metres

  4. 72 metres

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

Let L be the race length. A beats B by 12m, so A/L = B/(L-12). A beats C by 18m, so A/L = C/(L-18). B beats C by 8m, so B/L = C/(L-8). Using the ratios, (L-12)/L = (L-18)/(L-8). Solving for L: (L-12)(L-8) = L(L-18) => L^2 - 20L + 96 = L^2 - 18L => 2L = 96 => L = 48.

Multiple choice
  1. 6.5

  2. 7.75

  3. 9

  4. 10.5

  5. 11

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

Let u be upstream speed and d be downstream speed. 4/u + 4/d = 1. 3/u + 5/d = 55/60 = 11/12. Multiply first by 3 and second by 4: 12/u + 12/d = 3; 12/u + 20/d = 44/12 = 11/3. Subtracting: 8/d = 11/3 - 3 = 2/3. d = 12. Then 4/u + 4/12 = 1 -> 4/u = 2/3 -> u = 6. Speed in still water = (12+6)/2 = 9.

Multiple choice
  1. 67.2 km

  2. 33.6 km

  3. 45 km

  4. 90 km

  5. None of these

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

Speed downstream = 10 + 4 = 14 kmph. Speed upstream = 10 - 4 = 6 kmph. Let distance be D. Time = D/14 + D/6 = 8. (3D + 7D) / 42 = 8. 10D = 336. D = 33.6 km. Total distance (A to B and back) = 2 * 33.6 = 67.2 km.