Work through the levels in order. Type your answer and press Check — open the worked solution if you get stuck. Answers like -6, 3/4 or 0.25 are typed exactly as shown. A ⭐ Bonus Challenge at the end is extra credit — skip it if the rest was hard work.
Level 1 · Warm-up
1 Perth is 2 hours behind Sydney. It is 10 am in Sydney. What time is it in Perth?
Show worked solution
10 am − 2 h = 8 am.
2 Auckland is 2 hours ahead of Sydney. It is 1430 in Sydney. What time is it in Auckland (24-hour time)?
Show worked solution
1430 + 2 h = 16:30.
3 Perth is 2 hours behind Sydney and Auckland is 2 hours ahead of Sydney. How many hours is Auckland ahead of Perth?
Show worked solution
4 hours.
Level 2 · Core
4 Sydney is 17 hours ahead of Los Angeles. It is 0600 on Tuesday in Sydney. What day and time is it in Los Angeles?
Show worked solution
Tuesday 0000 − 11 h = Monday 1300.
5 Sydney is 17 hours ahead of Los Angeles. It is 2000 on Friday in Los Angeles. In Sydney it is Saturday — at what time (24-hour)?
Show worked solution
Friday 2000 + 17 h = Saturday 13:00.
6 Sydney is 17 hours ahead of Los Angeles and 2 hours ahead of Perth. How many hours is Perth ahead of Los Angeles?
Show worked solution
15 hours.
Level 3 · Challenge
7 A flight leaves Los Angeles at 2300 on Saturday, LA time, and takes 20 hours. Sydney is 17 hours ahead of LA.1 It lands at Sunday 1900, LA time.
2 It lands at Monday 1200, Sydney time.
3 When it takes off, it is Sunday 1600 in Sydney.
Which statements are correct?
2 It lands at Monday 1200, Sydney time.
3 When it takes off, it is Sunday 1600 in Sydney.
Which statements are correct?
Show worked solution
Sat 2300 + 20 h = Sun 1900 (1 ✓). + 17 h = Mon 1200 (2 ✓). Sat 2300 + 17 h = Sun 1600 (3 ✓). 1, 2 and 3.
8 A flight leaves Sydney at 1000 on Monday, Sydney time, and takes 14 hours to Los Angeles. LA is 17 hours behind Sydney. At what time does it land, in LA time (24-hour)? It lands on Monday.
Show worked solution
Tuesday 0000 − 17 h = Monday 07:00, three hours before take-off by the clock.
9 A plane leaves Perth at 0600 Perth time and flies 5 hours to Sydney. Sydney is 2 hours ahead of Perth. What does the Sydney clock read when it lands? Write it in 24-hour time as four digits, like 0930.
Show worked solution
1100 Perth time = 1300 Sydney time.