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Chapter overview
Learning goals
Learning Goals
Maths
Types of numbers
Number calculations
Fractions, decimals and percentages
Algebraic manipulation
Formulae and equations
Straight line graphs
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Ratio
Proportion
Rates of change
Shapes
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Lines and angles
Drawing shapes
Trigonometry
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Maths
Summary
Timetables are used in many places in society. They are a useful and organised way of displaying schedules.
Time is represented in two main formats: the $12$ hour system and the $24$ hour system.
12 hour system  24 hour system 


converting from 12 hour to 24 hour  Converting from 24 hour to 12 hour 


When adding and subtracting times, always remember that there are $60$ minutes in an hour.
How much time passes from $1{:}30pm$ to $5{:}15pm$?
First, find how much time is needed to get to the next hour:
The next hour is $2pm$. To get to $2pm$, you have to add $\textbf{30}$ minutes to $1{:}30pm$.
Then, find how much time is needed to get to $5pm$:
From $2pm$ to $5pm$, you have to add $52=\textbf{3}$ hours.
Find how much time is needed to get to $5{:}15pm$:
From $5pm$ to $5{:}15pm$, you have to add $\textbf{15}$ minutes.
Add all the times together:
$30$ minutes + $3$ hours + $15$ minutes = $3$ hours + $45$ minutes.
$\underline{3 \ \text{hours\ and} \ 45 \ \text{minutes}}$ passes from $1{:}30pm$ to ${5{:}15pm}$
Timetables are used to organise schedules. They are often used in bus and train stations and they tend to use the $24$ hour time format.
In the train timetable given, assume all trains take the same amount of time to make the same journey.
i) Find the values of $X$ and $Y$.
ii) A family is at Cambridge and wants to arrive at Paddington before $2{:}30pm$. What is the latest train they can take?
station  arrival times  
train a  train b  train c  
Cambridge  $11{:}02$  $12{:}15$  $Y$ 
Tottenham  $12{:}27$  $X$  $14{:}37$ 
Paddington  $13{:}00$  $14{:}13$  $15{:}10$ 
Surrey  $14{:}05$  $15{:}18$  $16{:}15$ 
Part i)
The time it takes for the trains to go from Cambridge to Tottenham is always the same.
So, to find $X$ and $Y$, first find how long it takes Train A to go from Cambridge to Tottenham:
This is the same as finding the time from $11{:}02$ to $12{:}27$:
$11{:}02$ to $12{:}00$: $+\,\textbf{58}$ minutes
$12{:}00$ to $12{:}27$: $+\,\textbf{27}$ minutes
So, the time it takes to go from Cambridge to Tottenham is:
$58+27=85$ minutes
Convert this to minutes and hours:
$85$ minutes $=1$ hour and $25$ minutes
Add this time onto $12{:}15$ to find the value of $X$:
$12{:}15+1$ hour $+\,25$