Q&A - PSLE Math

[Michaelia0816]

At 9.50 am, a lorry left Town J for Town K at an average speed of 54km/h. 50 minutes later, a car left Town K for Town J at an average speed equivalent to 150% that of the lorry. By noon, the lorry and the car was 30 km apart.

a) How far apart was Town J from Town K?
b) How far away from Town J did the lorry pass the car?

[Michaelia0816]

Raju started jogging from point G to point H at 1 pm while Abu started to cycle from Point H to point G at 2 pm. Abu was cycling 3 times the speed of Raju who was jogging at 6km/h. The distance between Point G to point H is 54km.

a) how far from G did they passed each other ?
b) At what time did they pass each other?

[small]

Please help with this speed question and many thanks in advance.


Question:
Mr Thomas left for Town B from Town A at 7.30am. He drove at an average speed of 70 km/h.Some time later, Mr Raja drove from Town A to Town B along the same route. He overtook Mt Thomas at 11.30am. 30minutes later, Mr Raja arrived at Town B while Mr Thomas was stil 5km away from Town B.

a) What was Mr Raja's average speed?
b) Find the distance between Town A and Town B.
c) At what time did Mr Raja leave Town A?

[MathIzzzFun]

small:

Please help with this speed question and many thanks in advance.


Question:
Mr Thomas left for Town B from Town A at 7.30am. He drove at an average speed of 70 km/h.Some time later, Mr Raja drove from Town A to Town B along the same route. He overtook Mt Thomas at 11.30am. 30minutes later, Mr Raja arrived at Town B while Mr Thomas was stil 5km away from Town B.

a) What was Mr Raja's average speed?
b) Find the distance between Town A and Town B.
c) At what time did Mr Raja leave Town A?

Hi

at 1130, Raja and Thomas were at the same point.
At 1200, Thomas travelled another 1/2 x 70 = 35 km, Raja travelled 35 + 5 = 40 km in 1/2 h
Raja's speed = 40 x 2 = 80 km/h .. b & c can then be calculated

cheers.

[tianzhu]

Michaelia0816:

At 9.50 am, a lorry left Town J for Town K at an average speed of 54km/h. 50 minutes later, a car left Town K for Town J at an average speed equivalent to 150% that of the lorry. By noon, the lorry and the car was 30 km apart.

a) How far apart was Town J from Town K?
b) How far away from Town J did the lorry pass the car?

Hi

From 9.50 am to 10.40 am, the lorry covered 45km

Car’s speed ------- 81 km/h

From 10.40am to noon --------- 80 mins

Car’s distance -------- 81*4/3 -------- 108
Lorry distance --------5 4*4/3 -------- 72

or combined together
(54+81)84/3 ------- 180

Distance between J and k --------- 180+30+45 --------- 225km

30/155 -------- 2/9h

Lorry covered 2/9*54 ------ 12 km

(b) 45+72+12 ---------- 129km

Best wishes

[tianzhu]

Michaelia0816:

Raju started jogging from point G to point H at 1 pm while Abu started to cycle from Point H to point G at 2 pm. Abu was cycling 3 times the speed of Raju who was jogging at 6km/h. The distance between Point G to point H is 54km.

a) how far from G did they passed each other ?
b) At what time did they pass each other?

Hi girl

From 1pm to 2pm, Raju covered 6km

54 – 6 ------- 48

Raju’s speed ------- 6 km/h
Abu’s speed ------ 18 km/h

48/24 ------- 2h

They met at 4 pm

In 2h, Raju covered 12km

Distance from G -------- 6 + 12 ------- 18 km

Best wishes

[small]

Many thanks again MathIzzzFun…


I realised my mistake, thought they were started from different towns.

[tianzhu]

Michaelia0816:

Help again with the following 3 questions!!!!!!


The diagram shows the road linking town p to town q.
P to q distance is 280km!
Roy passed P at 10am and reached q at 2 pm. Sam drove from p to q at a constant speed of 100km/h and arrived at a at 1.48pm.
a) when did Roy leave p?
b) when Sam reached town q, how far away from town q was Roy?

Hi

I don’t get to see the diagram, but based on your description, I’ll attempt to answer your question.

280/100 ------ 2.8h -------2h 48 minutes

(a)Roy left P at 10 am

Roy’s speed ------ 280/4 -------70km/h

Roy was 12 minutes away

12/60* 70 ------ 14 km

Best wishes

[tianzhu]

Hi Michaelia0816


Good morning, girl

I wish to heighten awareness that you’ve been posting too many questions.

I’ve raised this earlier. Are you having difficulties understanding them or just wanted to check the answers?

Perhaps your school teacher has just started out on the topic on Speed. Those questions you posted might be beyond your readiness. This may cause you to be unduly anxious as you are unable to cope.

If you are really having problems understanding the Speed concepts, may I suggest you approach your school teacher to straighten them out.

Understanding the basics and building up a firm foundation is the key to enhance your ability to cope with questions in the examinations.

Best wishes

[Michaelia0816]

Thank for the 3 questions! Now I can focus on the exam tomorrow!