year 8 maths

3J
Time
169
2 Find the number of:
a seconds in 2 minutes
b minutes in 180 seconds
c hours in 120 minutes
d minutes in 4 hours
e hours in 3 days
f days in 48 hours
g weeks in 35 days
h days in 40 weeks
3 What is the time difference between these times?
a 12 p.m. and 6:30 p.m.
b 12 a.m. and 10:45 a.m.
c 12 a.m. and 4:20 p.m.
d 11 a.m. and 3:30 p.m.
Example 20
4 C onvert these times to the units shown in the brackets.
a 3 h (min) b 10.5 min (s)
c 240 s (min) d 90 min (h)
e 6 days (h) f 72 h (days)
g 1 week (h) h 1 day (min)
i 14400 s (h) j 20160 min (weeks)
k 2 weeks (min) l 24 h (s)
5 Convert the following to hours and minutes. For parts f to i , use the ‘degrees, minutes and seconds’
button on a calculator to convert to hours, minutes and seconds.
a 2.5 hours b 3.25 hours c 1.75 hours
d 4.2 hours e 2.6 hours f 3.21 hours
g 2.38 hours h 7.74 hours i 6.03 hours
Example 21
6 Write these times using the system shown in the brackets.
a 1:30 p.m. ( 24 -hour)
b 8:15 p.m. ( 24 -hour)
c 10:23 a.m. ( 24 -hour)
d 11:59 p.m. ( 24 -hour)
e 0630 hours (a.m./p.m.)
f 1300 hours (a.m./p.m.)
g 1429 hours (a.m./p.m.)
h 1938 hours (a.m./p.m.)
i 2351 hours (a.m./p.m.)
7 Round these times to the nearest hour.
a 1:32 p.m.
b 5:28 a.m.
c 1219 hours
d 1749 hours
Cambridge Maths NSW
Stage 4 Year 8 Second edition
ISBN 978-1-108-46627-1 © Palmer et al. 2018
Cambridge University Press
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