Q&A - PSLE Math

[Michaelia0816]

Again Tianzhu, another question.

4. Jason left Town A for Town B. After travelling 5/8 of the distance, he passed Mary who was travelling in the same direction at a constant speed of 50km/h. It took Jason 2 hours to complete the remaining journey. When Jason reached Town B, Mary was still 80km away from Town B.
A) What is the distance between Town A and Town B?
B) What was Jason’s average speed?

[tianzhu]

Michaelia0816:

Again Tianzhu, another question.

4. Jason left Town A for Town B. After travelling 5/8 of the distance, he passed Mary who was travelling in the same direction at a constant speed of 50km/h. It took Jason 2 hours to complete the remaining journey. When Jason reached Town B, Mary was still 80km away from Town B.
A) What is the distance between Town A and Town B?
B) What was Jason's average speed?

Hi

Start with a simple diagram.

In 2h, Mary covered 2*50 or 100km

100 + 80 ----- 180

3/8 of journey or 3 units ----- 180

1 unit ------ 60

Distance ------- 8*60 -------480 (Distance between A and B)

Jason average speed ------- 180/2 ------ 90km/h

Best wishes

[Michaelia0816]

Thank again, I had to admit I didn’t think of that method to comple yeh.

[tianzhu]

Michaelia0816:

Thank again, I had to admit I didn't think of that method to comple yeh.

Hi

You're welcome.

You are a smart young lady.You'll get better.

Best wishes

[Michaelia0816]

I need help with the following next 7 questions! All step by step answer!



1) Mr Lee takes 3 minutes and 24 min to run up 24 steps and walk up 56 steps of a staircase. if he runs up 40 steps and walk up 40 steps, he will take 24 seconds less. If he runs at the same rate, how long will he take to run 80 steps? Give your answer in seconds.

2) Mr Tan was travelling from Sandy Town to Lawang Town. A truck travelling at a uniform speed of 60 km/h headed the same way.After completing 4/9 of the journey, Mr Tan passed the truck. 4 hour later, Mr Tan arrived at Lawang Town while the truck was still 10 km away from it.
A) How far was Lawang Town from Sandy Town?
B) At what time did Mr Tan leave Sandy Town if he reached Lawang Town at
3 pm

[Michaelia0816]

Next 2 questions…

3) Mr Kang wanted to travel from Town A to B. At first, he travelled at an average speed of 70 km/h. After travelling 84 km, ge increased his speed by 14 km/h to complete the remaining 1/3 of his journey.
A) What was the distance between Town A and Town B?
B) How much time could he saved if he travelled at a constant speed of 90km/h for the entire trip?

4) A car and a coach travelled from Town A to Town B. The coach left Town A at 0648 and it took 5 hr to reach Town B. The car started 30 min later than the coach and it took 4 hr to reach Town B. At what time did the car catch up the coach?

[Michaelia0816]

Next 3 question…

5) A cab driver drove from Town A To Town B. He passed a lorry driver who was driving at 100km/h in the opposite direction from Town B to Town A. One and a half hour after they passed each other, the cab driver arrived at Town B but the lorry driver was still 60km away from Town A.
A) Assuming that both drivers passed each other at mid-way between Town A and B, what is the total distance between the two towns?
B) If the lorry driver arrived in Town B at 1800, what time did he start to drive from Town A?

6) A van left Town X for Town Y at 8am. After travelling for 5hr at its usual speed,the van stopped for 30 min for lunch break. In order to reach Town Y at 4 pm, the speed of the van was increased by 16km/h.Find the distance between Town X and Town Y?

7)A car travelled from Town P to town Q at an average speed of 80km/h. at the same time, a bus travelled from Town Q to Town P at an average speed of 55 km/h. After travelling for 3/1/2 hours, the two vehicles were still 56km apart. Find the distance between the two towns?

[tianzhu]

Michaelia0816:

7)A car travelled from Town P to town Q at an average speed of 80km/h. at the same time, a bus travelled from Town Q to Town P at an average speed of 55 km/h. After travelling for 3/1/2 hours, the two vehicles were still 56km apart. Find the distance between the two towns?

Hi

Combined distance travelled by car ------ (80+55)*3.5 ------- 472.5

Distance between P and Q ------- 472.5+56 ------ 528.5km

Best wishes

[tianzhu]

Michaelia0816:

6) A van left Town X for Town Y at 8am. After travelling for 5hr at its usual speed,the van stopped for 30 min for lunch break. In order to reach Town Y at 4 pm, the speed of the van was increased by 16km/h.Find the distance between Town X and Town Y?

Hi

5h from 8am ------ 1pm
1pm ------- 4pm -------- 3h

But he increased speed by 16km/h to catch up with ½ h lunch.

In 2.5 h he covered (2.5*16) or 40 km more.

Usually the van took 1/2h to travel 40 km

Therefore its speed ------ 40*2 ------ 80 km/h

8am to 4pm ------8 h

Distance between X and Y -------- 80*8 ------ 640 km

Best wishes

[Michaelia0816]

Sorry to trouble u-.-, Tianzhu!!!