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 What is 2105 written in 12-hour time?
Show worked solution
21 − 12 = 9, so 9:05 pm.
2 A clock reads 1850. Write the 24-hour time a quarter of an hour later, as four digits, and the same time in 12-hour form.
Show worked solution
1905, which is 7:05 pm.
3 How many minutes are there in a quarter of an hour?
Show worked solution
15.
Level 2 · Core
4 A train leaves at 2245 and the journey takes 2 hours 30 minutes. When does it arrive?
Show worked solution
Midnight, then 1 h 15 min more: 0115.
5 A journey leaves Friday 1300 and takes 20 hours. Write the hours needed to reach midnight, and the arrival time as four digits.
Show worked solution
11 hours to midnight, then 9 more: 0900 on Saturday.
6 Sydney is 17 hours ahead of Los Angeles. It is 1900 on Sunday in Los Angeles. How many hours are needed to reach Monday 0000 in LA time?
Show worked solution
5 hours.
Level 3 · Challenge
7 A flight leaves Los Angeles at 2300 on Saturday and takes 20 hours. Sydney is 17 hours ahead.1 It lands at Sunday 1900, LA time.
2 In Sydney that is Monday 1200.
3 In Sydney that is Sunday 1200.
Which statements are correct?
2 In Sydney that is Monday 1200.
3 In Sydney that is Sunday 1200.
Which statements are correct?
Show worked solution
Sat 2300 + 20 h = Sun 1900 (1 ✓). + 17 h: 5 h to Monday 0000, then 12 more, so Monday 1200 (2 ✓, 3 ✗). 1 and 2.
8 A plane leaves Sydney at 1000 on Monday and flies 14 hours to Los Angeles, which is 17 hours behind Sydney. Write the Sydney time on landing and the Los Angeles time, both as four digits. It lands on Monday in LA.
Show worked solution
Sydney 0000 on Tuesday; 17 hours back is Monday 0700 in Los Angeles.
9 It is Saturday 0900 in one city and another is 17 hours ahead. How many hours past midnight is it in the second city? Give just the number.
Show worked solution
2 — it is Sunday 0200 there.