Questions

From Worst to Best

21 P6.SP.TL.18012283

Level 3
Singapore and Kuala Lumpur is 375 km apart. Rael left Singapore for Kuala Lumpur at 10.00 a.m. travelling at an average speed of 75 km/h. Sam left Singapore later than Rael and caught up with him at 12.00 p.m. Sam was travelling at a speed of 90 km/h.

At what time did Sam leave Singapore?
How much later did Rael arrive in Kuala Lumpur than Sam?

4 m

Attempt

22 P6.SP.TL.18012284

Level 3
At 8 a.m., Rina started from City A and travelled towards City B and his speed remained constant throughout. At 9 a.m., Mandy started her journey from City A towards City B at an average speed of 72 km/h. Mandy overtook Rina at 12 p.m. After overtaking, Mandy carried on her journey at the same average speed and reached at City B at 2:30 p.m.

Find Rina's average speed in km/h.
What is the distance between the two cities?

4 m

Attempt

DST triangle Average speed Same starting point Different starting time Overtaking Duration Start end time Timeline

23 P6.SP.TL.18012291

Level 3
Andy and Luke took part in a 24-km marathon. Andy ran half the distance at a speed of 10 km/h and jogged the rest of the way at a speed of 8 km/h. Luke ran half his total time at 12 km/h and jogged the rest of the time at 6 km/h. If they started the marathon at 7.30 a.m., at what time would each of them finish?

Andy
Luke

5 m

Attempt

DST triangle Average speed Journey by parts Different speed Same starting time Unit conversion Start end time Fraction of a whole

24 P6.SP.TL.18012294

Level 3
James started driving from Town A towards Town B at 13 40 at an average speed of 70 km/h. Melvin began driving from Town A towards Town B at 15 10 at an average speed of 100 km/h.