Time and Distance Aptitude Questions and Answers – Formulas & Tricks
Time and Distance Formula:
- Distance = Speed * Time,
- Time = Distance / Speed
- Speed = Distance / Time
- Average Speed = 2xy / (x + y)
- Convert Km/h to M/s =Km/h * (5/18)
- Convert m/sec to Km/hr = m/sec * (18/5)
- If the ratio of the speed of A and B is a : b, then the ratio of the times taken by them to cover the same distance is (1 / a) : (1 / b) or b : a
- Suppose a man covers a certain distance at x km/hr and an equal distance at y km/hr. Then, the average speed during the whole journey is (2xy / (x + y))km/hr.
- Using this formula, all basic problems can be handled. However, we need to make sure about the correct usage of units while using the formula
- Speed is inversely proportional to the time taken when distance travelled is constant. So When speed increases, time decreases and vice versa.
- Two persons may walk in same direction or in opposite direction
Relative Speed is defined as the speed of a moving object with respect to another. When two objects are moving in the same direction, relative speed is calculated as their difference. When the two objects are moving in opposite directions, relative speed is computed by adding the two speeds.
Time and Distance
90 * (10/60) = 15kmph
Let the actual distance travelled by x km.
Then, (x+10) = ((x+20)/14)
14x = 10x + 200
4x = 200
x = 50km
Let Abhay's speed be x km/hr
Then, (30 / x) - (30 / 2x) = 3
=> 6x = 30
x = 5km/hr
Let the distance travelled by x km.
Then, (x/10) - (x/15) = 2
3x - 2x = 60
x = 60km.
Time taken to travel 60km at 10km/hr = (60/10)hrs = 6hrs
So, Robert started 6hrs before 2PM. i.e., at 8AM
Therefore, Required Speed = (60/5)kmph
Required Speed = 12kmph
9x + 4(61-x) = 9 * 36
5x = 80
x = 16km
D = 110 + 170 = 280m
S = 60 * (5/18) = 50/3
T = 280 * (3/50) = 16.8sec
Relative speed of the thief and policeman = (11 - 10)km/hr = 1km/hr
Distance Covered in 6mins = (1/60) * 6km = 1/10km=100m
Therefore, Distance between the thief and policeman = (200 - 100)m = 100m.
Speed = 9km/hr = 9 *(5 / 18)m/sec = (5/2)m/sec
Distance = (35 *4)m = 140m
Time taken = 140 * (2/5)sec = 56 sec
Let the speeds of two trains be 7x and 8x km/hr
8x = 400/4
x = 12.5km/hr
So, Speed of first train is 12.5 * 7 = 87.5km/hr
The hour hand moves from pointing to 12 to pointing to half way between 2 and 3.
The angle covered between each hour marking on the clock is 360/12.
Since, the hand has covered 2.5 of these divisions the angle moved through is 75.