Time, Speed and Distance Questions

Multiple choice
  1. 12 km/h

  2. 6 km/h

  3. 8 km/h

  4. 4 km/h

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

Distance = 266 km, trains meet after 14 hours. Let slower train speed (from B) = x km/h, then faster train speed (from A) = (x+3) km/h. Relative speed = x + (x+3) = 2x + 3 km/h. Distance covered when they meet = 266 km. Time = 266 / (2x + 3) = 14 hours. So 266 = 14(2x + 3). 266 = 28x + 42. 28x = 224. x = 8 km/h. Therefore, train from B travels at 8 km/h.

Multiple choice
  1. 120

  2. 180

  3. 170

  4. 175

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

Distance = Speed × Time = 160 × 4.5 = 720 km. Speed needed to cover 720 km in 4 hours = 720/4 = 180 km/h. Speed and time are inversely proportional for fixed distance, so new speed = old speed × (old time/new time) = 160 × (4.5/4) = 180 km/h.

Multiple choice
  1. 25

  2. 50

  3. 30

  4. 20

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

Total time = 12 hours (7:30 am to 7:30 pm). Required speed = 500/12 = 41.67 km/h. By 12:30 pm (5 hours), only 30% (150 km) covered. Speed used = 150/5 = 30 km/h. Remaining 350 km in 7 hours needs speed = 350/7 = 50 km/h. Increase needed = 50 - 30 = 20 km/h, which is option D.

Multiple choice
  1. 350

  2. 351

  3. 353

  4. 359

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

Average speed = total distance / total time. Let distance be 100 km. Times: 25 km at 300 km/hr = 0.0833 hr, 20 km at 200 km/hr = 0.1 hr, 55 km at 550 km/hr = 0.1 hr. Total time = 0.2833 hr. Average speed = 100/0.2833 ≈ 353 km/hr.

Multiple choice
  1. 5 hour and 30 minutes

  2. 4 hours

  3. 5 hours

  4. 4 hours and 30 minutes

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

Downstream speed = boat speed + current speed = 25 + 5 = 30 km/hr. Time = distance/speed = 135/30 = 4.5 hours = 4 hours 30 minutes. Option A incorrectly adds time, B and C are calculation errors.

Multiple choice
  1. 4 hours 4 घंटे

  2. 4 hours 5 minutes 4 घंटे 5 मिनट

  3. 4 hours 30 minutes 4 घंटे 30 मिनट

  4. 2 hours 2 मिनट

  5. None of these इनमें से कोई नहीं

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

Speed starts at 70 km/h, increases by 10 km/h every 2 hours. First 2 hours: 70 km/h covers 140 km. Next 2 hours: 80 km/h covers 160 km. Total in 4 hours = 300 km. Remaining distance = 345 - 300 = 45 km. Speed for next 2 hours = 90 km/h, so 45 km takes 45/90 = 0.5 hours = 30 minutes. Total time = 4 hours 30 minutes.

Multiple choice
  1. $220 m/sec$
  2. $330 m/sec$
  3. $300 m/sec$
  4. $270 m/sec$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The echo travels from the person to the hill and back, covering twice the distance (720m total). Speed = Distance / Time = 720 / 2.4 = 300 m/sec. This is the standard calculation for echo-based speed of sound problems.

Multiple choice
  1. 42 Km 42 किमी

  2. 22 Km 22 किमी

  3. 33 km 33 किमी

  4. 42.03 km 42.03 किमी

  5. None of these. इनमे से कोई नहीं

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

If traveling downstream with current at 25+3 = 28 km/hr for 1.5 hours, distance = 42 km. But the question asks for river width, which is perpendicular to flow. The ship length (15m) is irrelevant and unit-inconsistent. Neither width nor crossing time can be determined from given data.

Multiple choice
  1. 20 km 20 किमी

  2. 30 km 30 किमी

  3. 40 km 40 किमी

  4. 45 km 45 किमी

  5. None of these तय नहीं कर सकते हैं

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

Let original speed be v km/hr, then P = vt. When speed increases by 3 km/hr: P/(v+3) = t - 2/3 hours. When speed decreases by 2 km/hr: P/(v-2) = t + 2/3 hours. Substituting P = vt and solving gives v = 12 km/hr, t = 10/3 hours, so P = 40 km. The key is converting 40 minutes to 2/3 hours and setting up the inverse relationship between speed and time.

Multiple choice
  1. 110 km

  2. 160 km

  3. 130 km

  4. 150 km

  5. None of these

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

Car speed = 120/4 = 30 km/h. Boat is 16(2/3)% more = 1/6 more, so boat speed = 35 km/h. Downstream: boat + stream = 164/4 = 41 km/h, so stream = 6 km/h. Upstream: boat - stream = 35 - 6 = 29 km/h. Distance in 5 hours = 29 × 5 = 145 km. None of the options (110, 160, 130, 150) match 145 km, so "None of these" is correct.

Multiple choice
  1. 58.4

  2. 66.6

  3. 69.3

  4. 63.8

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

Let initial speed = v km/h. Hour 1: distance = v. Hour 2: speed = 1.1v, distance = 1.1v. Hour 3: speed = 1.21v, distance = 1.21v. Total: v + 1.1v + 1.21v = 3.31v = 198.6, so v = 60. Hour 2 speed = 66, Hour 3 speed = 72.6. Avg last 2 hrs = (66 + 72.6)/2 = 69.3 km/h. The progressive 10% increases create this average.

Multiple choice
  1. 16 km/h

  2. 30 km/h

  3. 40 km/h

  4. 20 km/h

  5. 15 km/hr

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

Let normal speed = v km/h, time = t hours. Distance = vt = 80. Late by 1 hour, new speed = v+4, time = t-1. Distance = (v+4)(t-1) = 80. Since vt = 80, we have vt + 4t - v - 4 = vt. 4t - v - 4 = 0. Also t = 80/v. Substitute: 4(80/v) - v - 4 = 0. 320/v - v - 4 = 0. Multiply by v: 320 - v² - 4v = 0. v² + 4v - 320 = 0. (v+20)(v-16) = 0. v = 16 (positive). New speed = v+4 = 20 km/h.

Multiple choice
  1. 456 km

  2. 588 km

  3. 528 km

  4. 800 Km

  5. None of these

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

First train travels for 45 minutes (0.75 hours) alone: distance = 96 × 0.75 = 72 km from A. Remaining distance = 856 - 72 = 784 km. When both trains move toward each other, relative speed = 96 + 100 = 196 km/h. Time to meet = 784 ÷ 196 = 4 hours. In this time, first train covers additional 96 × 4 = 384 km. Total from A = 72 + 384 = 456 km. Option B (588) incorrectly uses only the relative speed portion.