Time, Speed and Distance Questions

Multiple choice
  1. 3 : 5

  2. 5 : 3

  3. 1 : 5

  4. 5 : 1

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

Speed against current (u-v) = (3/4 km) / (15/60 h) = 3 km/h. Speed with current (u+v) = (3/4 km) / (10/60 h) = 4.5 km/h. Solving u-v=3 and u+v=4.5 gives 2u=7.5 (u=3.75) and 2v=1.5 (v=0.75). Ratio u:v = 3.75:0.75 = 5:1.

Multiple choice
  1. 6 km

  2. 9 km

  3. 4 km

  4. 3 km

  5. 2 km

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

Let distance be D. Time taken at 5 km/h is D/5. Time taken at 6 km/h is D/6. Given (D/5) - (D/6) = (5+7)/60 = 12/60 = 1/5. Solving D/30 = 1/5 gives D = 6 km.

Multiple choice
  1. 10 km/hr and 30 km/hr

  2. 40 km/hr and 10 km/hr

  3. 40 km/hr and 30 km/hr

  4. 90 km/hr and 70 km/hr

  5. 10 km/hr and 90 km/hr

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

Let speeds be u and v. Relative speed in same direction is u - v = 90/9 = 10. Relative speed in opposite direction is u + v = 90/(9/7) = 70. Solving the system u - v = 10 and u + v = 70 gives u = 40 and v = 30.

Multiple choice
  1. 8.50 km

  2. 7.51 km

  3. 6.50 km

  4. 5.60 km

  5. None of these

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

Jem beats Sem by 2 km in 40 km, so Jem:Sem = 40:38. Sem beats Kem by 4 km, so Sem:Kem = 40:36 = 10:9. Kem beats Jesu by 2 km, so Kem:Jesu = 40:38 = 20:19. Ratio Jem/Jesu = (40/38) * (40/36) * (40/38) = (20/19) * (10/9) * (20/19) = 4000 / 3249. Distance = 40 * (1 - 3249/4000) = 40 * (751/4000) = 7.51 km.

Multiple choice
  1. Only A and B together are sufficient.

  2. Only A and C together are sufficient.

  3. Only B and C together are sufficient.

  4. Any two of them together are sufficient.

  5. All three statements are necessary.

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

Average speed = Total distance / Total time. Statement A gives the ratio of speeds. Statement B gives the walking speed (8km / 2hr = 4km/h). Statement C gives the total distance. To find the average speed, we need the total time, which requires both the walking speed (from B) and the jogging speed (from A). C is redundant if we know the distance is covered in a specific route.

Multiple choice
  1. 7 hours and 12 minutes

  2. 8 hours

  3. 8 hours and 34 minutes

  4. 9 hours

  5. 9 hours and 14 minutes

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

Let x be highway time. Then (18-x) is city time. 64x + 42(18-x) = 932. 64x + 756 - 42x = 932. 22x = 176. x = 8 hours.

Multiple choice
  1. 100 km/hour

  2. 80 km/hour

  3. 10 km/hour

  4. 15 km/hour

  5. 20 km/hour

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

Let boat speed be v. Downstream speed = v + 1. Upstream speed = v - 1. Time difference: 99/(v-1) - 99/(v+1) = 2. 99 * (v+1 - v+1) / (v^2 - 1) = 2. 99 * 2 / (v^2 - 1) = 2. 99 = v^2 - 1. v^2 = 100, v = 10.

Multiple choice
  1. 36 km

  2. 40 km

  3. 42 km

  4. 45 km

  5. 48 km

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

Let speed of A = 4k, B = 5k. Current speed = 5. Current relative to A = 1/4 * 4k = k = 5. So speed of A = 20, B = 25. Downstream speed of B = 25 + 5 = 30. Distance = 30 * 1.5 = 45 km.