my kid came back with the working for the first speed question which I have asked earlier , i don’t understand can you please explain?

60 mins ----20 km
10 mins ---- 20km÷ 60 = 3 1/3
40 km ÷3 1/3 =12
12× 10 min= 120 min
120min ÷2 =60
60 +20 =80
Can you explain the logic on this working? thank you

Hi, mathsguru I don’t understand why it is 64 2 -522=24 is the answer for the speed question.

thank you for your help. there is another speed question.


Mr Tan drove from city X to city Y.At the same time,Mr Koh drove from city Y to city X.They passed each other 64 km away from city Y and continued their journeys. They made a u-turn upon reaching their destinations so that they could return to their own cities. They passed each other again 52 km away from city X.Find the distance between the two places when they met each other.

hi mathguru

thank you for your help.however I still don’t understand what does ‘n’ represent ? please explain more clearly .Thank you.

Mr Tan drives to work everday .The distance from home to office is 40 km.He was sick one day and he drove 20km/h slower and was 10 minutes late for work.what was his usual speed to work?