Quantitative Aptitude

Time, Speed and Distance

2,165 Questions
All Core formulas and unit conversion 441 Boats and streams effective speed 396 Relative speed, meetings, and overtaking 375 Average speed 362 Early and late arrival 321 Proportional relationships 202 Stoppage time per hour 35 Train and stationary or moving object crossing 17 Races and dead heats 16

Time, Speed and Distance Questions

Multiple choice

A man decided to cover a distance of 6 km in 84 minutes. He decided to cover two thirds of the distance at 4 km / hr. and the remaining at some different speed. Find the speed after the two third distance has been covered?

  1. 5kmph

  2. 7kmph

  3. 9kmph

  4. 3kmph

  5. 4kmph
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total distance 6 km, time 84 min (1.4 hours). Two-thirds distance = 4 km. Time taken at 4 km/h = 4/4 = 1 hour. Remaining distance = 2 km. Remaining time = 1.4 - 1 = 0.4 hours. Speed = 2 / 0.4 = 5 km/h.

Multiple choice

Three runners Dexter, Micheal and Frodo are running a race in water with Dexter finishing 20 m ahead of Micheal and 34 m ahead of Frodo, while Micheal finishes 21 m ahead of Frodo. Each of the three participants are running with a constant speed during the race. Each runner travels the entire distance at a constant speed. What was the length of the pool in which the race was taking place?

  1. 40 m

  2. 50 m

  3. 60 m

  4. 80 m

  5. 90 m
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let L be the length. Dexter finishes at L, Micheal at L-20, Frodo at L-34. When Micheal finishes at L, Frodo is at L-21. The ratio of speeds of Micheal to Frodo is L / (L-21). Also, the ratio of speeds is (L-20) / (L-34). Equating: L/(L-21) = (L-20)/(L-34). L^2 - 34L = L^2 - 41L + 420. 7L = 420, L = 60.

Multiple choice

In a flight of 2,800 km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 100 km/hr and time of flight increased by 30 minutes. What was the original average speed of the aircraft?

  1. 700 km/hr

  2. 750 km/hr

  3. 800 km/hr

  4. 900 km/hr
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let original speed be v. 2800/v - 2800/(v-100) = -0.5. Solving this quadratic: 2800(v-100) - 2800v = -0.5v(v-100). -280000 = -0.5v^2 + 50v. v^2 - 100v - 560000 = 0. (v-800)(v+700) = 0. v = 800.

Multiple choice

A train X takes 2 hours less than a train Y to cover a distance of 192 km between two cities. Their average speeds differ by 16 km/hr. How long does the faster train take to cover the journey?

  1. 3 hours

  2. 4 hours

  3. 5 hours

  4. 6 hours
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let speed of Y be v, then speed of X is v + 16. Time taken: 192/v - 192/(v+16) = 2. Simplifying: 192(v+16-v) = 2v(v+16) => 96 * 16 = v^2 + 16v => v^2 + 16v - 1536 = 0. Solving gives v = 32. Faster train X speed = 48. Time = 192/48 = 4 hours.

Multiple choice

A boat is moving from the east bank to the west bank on a south 'flowing river. The speed of the boat is 4 km/h and that of the river is 3 km/h. If the width of the river is 2 km, the distance travelled by the boat is

  1. 5 km

  2. 4 km

  3. 3 km

  4. 2.5 km

  5. 2 km
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The boat travels across the river (width 2 km). The resultant velocity is the vector sum of the boat speed (4 km/h) and river speed (3 km/h). The time taken to cross is 2/4 = 0.5 hours. In this time, the boat drifts downstream, but the question asks for the distance travelled by the boat relative to the ground, which is sqrt(4^2 + 3^2) * 0.5 = 5 * 0.5 = 2.5 km.