At a robotics workshop, the sessions run one after another with no breaks in between. The workshop starts at 13 40.
- The 1st session lasts 45 min, the 2nd session lasts 1 h 15 min and the 3rd session lasts 55 min. How long do the first three sessions last altogether? Give your answer in hours and minutes.
- At what time does the 4th session start? Give your answer in 24-hour clock.
Need a hint?
Add the three session lengths first, then add that total to the starting time. Use the hour and minute parts separately.
Worked answer
- (a) Add the three durations: 45 min + 1 h 15 min + 55 min = 2 h 55 min.
- (b) Add 1 hour to 13 40 to get 14 40, then add another hour to get 15 40.
- Add the remaining 55 min: 15 40 + 55 min = 16 35.
- Answer: 16 35 in 24-hour clock.
Answer: 16 35 24-hour
The mistake this question tests
Habit
Calculation slip
Pupils often add the minutes and hours without carrying 60 minutes into an hour, or leave the answer as 4 35 rather than using the 24-hour clock.
How to fix it at home →More PSLE measurement questions
MCQ · 1m
Ravi boarded a train at 9.40 a.m
See the answer →Short answer · 2mNina's blue ribbon is 5.6 cm long
See the answer →MCQ · 1mFarid played a chess match at a community club
See the answer →Structured · 4mAt a food stall, Mr Tan nests identical reusable takeaway boxes
See the answer →Short answer · 2mNoah's drama rehearsal lasted 120 min
See the answer →Structured · 5mTank P and Tank Q are rectangular tanks
See the answer →Practise PSLE measurement until the mistakes stop.
Three PSLE questions, free, no sign-up. You’ll see exactly where the marks went. Then 7 days of everything for S$4.99.