Time, Speed and Distance Questions

Multiple choice
  1. 20 minutes

  2. 30 minutes

  3. 35 minutes

  4. 45 minutes

  5. 48 minutes

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

John speed = 1200/8 = 150 m/min. Sarah speed = 1200/10 = 120 m/min. Relative speed = 150 - 120 = 30 m/min. They start at opposite points (300m apart). To catch up the first time, John must cover the 300m gap. Time = 300 / 30 = 10 min. To catch up the second time, he must cover another 600m (the full track). Time = 600 / 30 = 20 min. Total time = 10 + 20 = 30 min.

Multiple choice
  1. 25.625 miles

  2. 30.5 miles

  3. 32.625 miles

  4. 35.625 miles

  5. 45.625 miles

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

Initial speed = 25 mph. Time = 40 mins = 2/3 hours. Distance = 25 * 2/3 = 50/3 miles. Time remaining = 9:45 - 8:30 = 75 mins. Time spent = 40 mins. Time left = 35 mins. New speed = 25 * 1.3 = 32.5 mph. Distance covered in 35 mins = 32.5 * (35/60) = 32.5 * (7/12) = 18.958 miles. Total distance = 16.66 + 18.958 = 35.625 miles.

Multiple choice
  1. 11:30 PM

  2. 7:50 PM

  3. 5:10 PM

  4. 8:10 PM

  5. 10:36 PM

Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice
  1. 320.43 km

  2. 411.43 km

  3. 420 km

  4. 480 km

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

Let total distance be D. Time = (D/2)/60 + (D/2)/80 = 6. D/120 + D/160 = 6. (4D + 3D) / 480 = 6. 7D = 2880. D = 411.43 km.

Multiple choice
  1. 50 kmph

  2. 40 kmph

  3. 30 kmph

  4. 25 kmph

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

Normal time = 100/v. First half (50km) at speed v takes 50/v. Second half (50km) at v/2 takes 100/v. Total time = 50/v + 100/v = 150/v. Difference: 150/v - 100/v = 2. 50/v = 2, so v = 25 kmph.

Multiple choice
  1. 1 minute

  2. 1 minutes and 35 seconds

  3. 2 minutes

  4. 2 minutes and 12 seconds

  5. 5 minutes

Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice
  1. 55.5 km/hr

  2. 60.5 km/hr

  3. 65.7 km/hr

  4. 68.6 km/hr

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

The smallest 4-digit square is 32^2 = 1024. The smallest 4-digit palindrome > 1200 is 1221. The distance covered is 1221 - 1024 = 197 km. Let v be the initial speed. He drives 1 hour at v and 1 hour at 2v, covering 3v = 197 km. Thus, v = 65.66... km/hr. Since the speed was constant until 10:00 A.M., the speed at 9:50 A.M. is 65.7 km/hr.

Multiple choice
  1. 80 miles per hour

  2. 90 miles per hour

  3. 120 miles per hour

  4. 125 miles per hour

  5. 130 miles per hour

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

Let speed be v. Time taken at speed v is 240/v. Time taken at speed (v-40) is 240/(v-40). The difference is 240/(v-40) - 240/v = 3. Solving this quadratic equation: 240v - 240(v-40) = 3v(v-40) leads to 9600 = 3v^2 - 120v, or v^2 - 40v - 3200 = 0. Factoring gives (v-80)(v+40) = 0, so v = 80.