Qn 10 a) Distance already travelled = 54km/h x 2/3h = 36km

Remaining distance = 120km - 36km = 84km

Remaining time = 2h - 2/3hr = 1 1/3h

Average speed = 84km ÷ 1 1/3h = 63km/h

b) i) average speed = 120km ÷ 2 1/6h = 55 1/3km/h

ii) Total distance = 120km + 120km = 240km

Total time = 2h + 2 1/6h = 4 1/6h

Average speed = 240km ÷ 4 1/6h = 57 3/5km/h OR 57.6km/h

(a)

ReplyDelete1st step : 2/3 looks like 2/5. Never explain how u convert from 40 min to 2/5

3rd step: Never explain how u get 2/3 hour

4th step: You said 64km/h but the paper write is 63km/h

(b)

(i) Never explain how you get 2 1/6h

(ii) Again, never explain how you get 2 1/6h

Presentation: 1

Mathematical terms: 1

Explanation of working/solution : 1

Understanding of concepts: 2

Accuracy of answer: 2

Total: 7

Mathematical Terms [0] (Not much terms used)

ReplyDeleteExplanation of Solution [3]

Understanding of Concepts [2]

Accuracy of Answers [2]

Presentation [2]

Total: 9

G-O-O-D-J-O-B

@ Jia Qi : When you mean by explaining, does it mean I have to explain the workings?

ReplyDelete1. The approach to solve (a) is clearly explained.

ReplyDelete2. The explanation to all the part are very clear.

3. Read "k""m" as kilometres; also write "hr" as "h".