Time, Speed and Distance Questions

Multiple choice
  1. 20 km

  2. 30 km

  3. 35 km

  4. 40 km

  5. None of these

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

Amit travels for 0.5 hours at 12 km/h, covering 6 km before Bimal starts. The relative speed of Bimal to Amit is 15 - 12 = 3 km/h. Bimal needs 6 km / 3 km/h = 2 hours to catch up to Amit. In these 2 hours, Bimal travels 15 km/h * 2 hours = 30 km.

Multiple choice
  1. 2 hours and 45 minutes

  2. 3 hours and 15 minutes

  3. 3 hours and 45 minutes

  4. 4 hours and 15 minutes

  5. 4 hours and 45 minutes

Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice
  1. 4 hours

  2. 6 hours

  3. 8 hours

  4. They never meet.

  5. a

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

Speeds form a GP with r = 0.5. Speed of A at hour n: 80 * (0.5)^(n-1). Speed of B at hour n: 88 * (0.5)^(n-1). Sum of distances covered in 4 hours: Sum = (a(1-r^n))/(1-r). For A: 80(1-0.5^4)/(1-0.5) = 160(0.9375) = 150. For B: 88(1-0.5^4)/(1-0.5) = 176(0.9375) = 165. Total distance = 150 + 165 = 315.

Multiple choice
  1. 63 km

  2. 13 km

  3. 12.6 km

  4. 13.6 km

  5. a

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

Let the one-way distance be d km. The running time is d/12 + d/18 hours, and the total elapsed time excluding the 20-minute rest is 1 hour 45 minutes, or 1.75 hours. Solving gives d × 5/36 = 1.75, so d = 12.6 km.

Multiple choice
  1. 17,190 km

  2. 15,670 km

  3. 12,865 km

  4. 8,970 km

  5. a

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

Total vehicles = 510. Ratios: C:M = 3:5, M:B = 2:7. C:M:B = 6:10:35. Total parts = 51. Each part = 10. Cars = 60, Motorcycles = 100, Bicycles = 350. Electric: 0.4*60=24, 0.25*100=25, 0.16*350=56. Conventional: 36, 75, 294. Distance = (24+25+56)*30 + (36*60 + 75*80 + 294*20) = 105*30 + 2160 + 6000 + 5880 = 3150 + 14040 = 17190.

Multiple choice
  1. 16 π

  2. 12 π

  3. 18 π

  4. 14 π

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

Let distance be D. Revolutions for A = D / (2 * pi * 30), for B = D / (2 * pi * 40). D/(60pi) - D/(80pi) = 5000. D/(240pi) = 5000, D = 1,200,000 * pi cm = 12 * pi km. Speed = Distance / Time = (12 * pi) / (45/60) = 12 * pi / 0.75 = 16 * pi km/hr.

Multiple choice
  1. 1 : 4

  2. 7 : 5

  3. 5 : 7

  4. 4 : 1

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

Let distance AB = d, then BC = 3d. Train 1 speed on AB = v, on BC = 2v. Train 2 speed on AB = 2v, on BC = v. Time for T1 = d/v + 3d/2v = 5d/2v. Time for T2 = d/2v + 3d/v = 7d/2v. Ratio T1:T2 = 5:7.

Multiple choice
  1. 29

  2. 27

  3. 28

  4. 26

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

Usual time = D/40. Late by 6 min (0.1 hr) at 35 km/hr: D/35 - D/40 = 0.1. D/280 = 0.1, D = 28 km. Usual time = 28/40 = 0.7 hr (42 min). One day: 2/3 distance (18.66 km) in 1/3 time (14 min). Remaining distance = 9.33 km. Remaining time = 42 - 14 - 8 = 20 min (1/3 hr). Speed = 9.33 / (1/3) = 28 km/hr.

Multiple choice
  1. 4.2

  2. 5.2

  3. 4.8

  4. 4.6

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

Time for Anil to complete a lap = 3/15 = 1/5 hr. Time for Sunil = 3/10 = 3/10 hr. They meet at the start when time is a multiple of both 1/5 and 3/10. LCM(1/5, 3/10) = 3/5 hr. In 3/5 hr, Ravi (speed 8 km/hr) runs 8 * 0.6 = 4.8 km.

Multiple choice
  1. 150

  2. 100

  3. 90

  4. 120

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

Let speeds be v1 and v2. (v1+v2) * 1.5 = D. (v1-v2) * 10.5 = D. 1.5(v1+v2) = 10.5(v1-v2). v1+v2 = 7(v1-v2). v1+v2 = 7v1-7v2. 8v2 = 6v1. v1 = 4/3 * v2. If v2=60, v1=80. D = (80+60)*1.5 = 140*1.5 = 210. Distance by slower car = 60 * 1.5 = 90.