Arrival & Departure Times (SQA National 5 Applications of Mathematics): Revision Note
Exam code: X844 75
Arrival times
How do I add minutes and hours when going above 60 minutes or 24 hours?
Hours
Consider adding 15 hours to 16:30 on 3 May
Add the hours
e.g. 16 hours + 15 hours = 31 hours
Subtract 24 hours
e.g. 31 hours - 24 hours = 7 hours
Add 1 day to the date
e.g. 07:30 on 4 May
Minutes
Consider adding 37 minutes to 07:30
Add the minutes
e.g. 30 minutes + 37 minutes = 67 minutes
Subtract 60 minutes
e.g. 67 minutes - 60 minutes = 7 minutes
Add 1 hour to the time
e.g. 08:07
How do I find the arrival time and date?
You might have to find the arrival time given:
the departure time
the journey time
You need to add the journey time to the departure time
Do this in stages
Divide the hours of the journey by 24 to find the number of full days and remaining hours
Write the departure time in 24-hour format
Add 12 to the hours if it is pm
Add the full days onto the departure time
The time stays the same
The date changes
Add the remaining hours
The hours change
The minutes stay the same
The date might change if you go above 24 hours
Add the minutes
The minutes change
The hours might change if you go above 60 minutes
The date might change if you go above 24 hours
Add or subtract the time difference to find the local time of the destination
You can do this at the start or at the end
The date might change if you go below 0 hours or above 24 hours
Examiner Tips and Tricks
You can give your answer using either the 24-hour format or am/pm.
Worked Example
Elena travels from Edinburgh to Madrid by car and boat.
The journey takes a total of 26 hours and 35 minutes.
Elena leaves Edinburgh at 10:50 pm local time on 3 March.
Madrid is 1 hour ahead of Edinburgh.
Determine the local time and date Elena arrives in Madrid.
Answer:
Divide 26 hours by 24 hours to get the number of full days and remaining hours
26 hours = 1 day and 2 hours
Write the departure time using 24-hour format
10:50 pm = 22:50
Add the full days to the departure time
3 March + 1 day = 4 March
4 March 22:50
Add the remaining hours
This adds 1 to the date as it crosses 24 hours
22 hours + 2 hours = 24 hours = 1 day and 0 hours
5 March 00:50
Add the minutes
This adds one to the hours as it crosses 60 minutes
50 minutes + 35 minutes = 85 minutes = 1 hour and 25 minutes
5 March 01:25
Add the time difference as Madrid is ahead
5 March 01:25 + 1 hour = 5 March 02:25
5 March 02:25 or 2:25 am
Departure times
How do I subtract minutes and hours when going below zero?
Hours
Consider subtracting 5 hours from 02:30 on 3 May
Subtract the available amount to take you to 0 hours
e.g. 02:30 - 2 hours = 00:30
See how many hours are left to subtract
e.g. 5 hours - 2 hours = 3 hours left
Subtract the remaining hours from 24 hours
e.g. 24 hours - 3 hours = 21 hours
Subtract 1 day from the date
e.g. 21:30 on 2 May
Minutes
Consider subtracting 42 minutes from 21:30
Subtract the available amount to take you to 0 minutes
e.g. 21:30 - 30 minutes = 21:00
See how many minutes are left to subtract
e.g. 42 minutes - 30 minutes = 12 minutes left
Subtract the remaining minutes from 60 minutes
e.g. 60 minutes - 12 minutes = 48 minutes
Subtract 1 hour from the time
e.g. 20:48
How do I find the departure time and date?
You might have to find the departure time given:
the arrival time
the journey time
You need to subtract the journey time from the arrival time
Do this in stages
Divide the hours of the journey by 24 to find the number of full days and remaining hours
Write the arrival time in 24-hour format
Add 12 to the hours if it is pm
Subtract the full days from the arrival time
The time stays the same
The date changes
Subtract the remaining hours
The hours change
The minutes stay the same
The date might change if you go below 0 hours
Subtract the minutes
The minutes change
The hours might change if you go below 0 minutes
The date might change if you go below 0 hours
Add or subtract the time difference to find the local time of the starting point
You can do this at the start or at the end
The date might change if you go below 0 hours or above 24 hours
Worked Example
Anthony travels from Hull to Oxelösund by ship.
Hull is 1 hour behind Oxelösund.
The journey took 90 hours and 15 minutes.
The ship arrives in Oxelösund at 4:05 pm local time on 17 September.
Calculate the date and local time that the ship left Hull.
Answer:
Divide 90 hours by 24 hours to get the number of full days and remaining hours
90 ÷ 24 = 3 remainder 18
90 hours = 3 days and 18 hours
Write the arrival time using 24-hour format
4:05 pm = 16:05
Subtract the full days from the arrival time
17 September - 3 days = 14 September
14 September 16:05
Subtract the remaining hours
This subtracts 1 from the date as it crosses 0 hours
16:05 - 16 hours = 00:05
18 hours - 16 hours = 2 hours left
24 hours - 2 hours = 22 hours
13 September 22:05
Subtract the minutes
This subtracts one from the hours as it crosses 0 minutes
22:05 - 5 minutes = 22:00
15 minutes - 5 minutes = 10 minutes left
60 minutes - 10 minutes = 50 minutes
13 September 21:50
Subtract the time difference as Hull is behind
13 September 21:50 - 1 hour = 13 September 20:50
13 September 20:50 or 8:50 pm
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