Q&A - PSLE Math

[tianzhu]

Nanyang P6 Prelim 2010 P2: Q10. Kingsley planned to cycle from Town P to Town Q. If he were to cycle at 10 km/h, he would reach Town Q at 7.45 p.m. If he were to cycle at 12 km/h, he would reach Town Q at 7.15 p.m. What was the distance between Town P and Town Q? [3 marks][Answer given: 30 km]


Hi
Hope this helps.

Speed --- 12:10 ------ 6:5
Time --- 5:6
1 unit -----1/2h (30mins)
5 units ------ 5/2 h
Distance between P and Q -------5/2*12 -------30km

Best wishes

[tianzhu]

SHHK P6 Prelim 2010 P2

Q15: A car and a van started travelling from Town X to Town Y at the same time. The distance between the two towns was 225 km. Both vehicles did not change their speed. The car arrived at Town Y ¾ h earlier than the van. When the car reached Town Y, the van was still 45 km away from Town Y. What was the speed at which the car was travelling [4 marks][Answer given: 75 km/h]
Hi

Hope this helps

Consider the van first
Distance ------45
Time ------- ¾
Speed of van ------- 60km/h

Time taken by van to travel 225km
225/60 ------- 3 3/4h (3.75h)

Therefore the car took 3h to travel 225km
Hence, speed of car -------225/3 -------75km/h

Best wishes

[tianzhu]

CHIJ St Nic P6 Prelim 2010 P2

Q15: Kitty Town and Melody Town are 234 km apart. Danny left Kitty Town for Melody Town at 8.42 a.m. travelling at an average speed of 85 km/h. At the same time, Jasmine left Melody Town for Kitty Town. They met each other at 10.30 a.m. (a) What was Jasmine’s average speed when she met Danny? (b) If Jasmine were to increase her speed by 26 km/h before meeting Danny, how much less time would she take before meeting him? [4 marks][Answer given: 45 km/h, 18 min]

Hi
Hope this helps

a)Time ------ 1h 48min ------I 4/5h
Distance travelled by Danny ------85*9/5 ------ 153km

Distance travelled by Jasmine ------234 -153 ------81km
Speed of Jasmine --------81/ 9/5 ---------45km/h

b)If her speed is increased to 71km/h (45+26)

Time taken by Jasmine ----- 234/(71+85) ------1.5h

Therefore she took 18 min less (1h 48min minus 1 h 30min)

Best wishes

[tianzhu]

Rosyth P6 Prelim 2010 P2

Q17: A tour bus which left Kuala Lumpur at 10.30 a.m. was scheduled to reach Singapore by 5 p.m. After travelling for 2 hours at its usual speed, the bus stopped for 30 minutes due to some problems. In order to reach Singapore punctually, the bus increased its speed by 8.5 km/h. Given that the bus took 4 hours to complete the rest of the journey, find the distance between Kuala Lumpur and Singapore.[5 marks][Answer given: 442 km]

Hi
Hope this helps

Original time from KL to Singapore ----- 6.5h

Consider the second half of journey

Time ------- 4: 4.5 ------- 8:9
Speed -------9:8

1 unit -----8.5km/h
8 units ------ 68 km/h

Distance between Kuala Lumpur and Singapore ------68*6.5 ----- 442km

Best wishes

[tianzhu]

Pei Chun P6 Prelim 2010 Paper 2

Q16: The distance between Town U and Town V is 374.25 km. A car left Town U at 2115 for Town V, travelling at 85 km/h. A van left Town V at 2245 for Town U on the same road, travelling at a certain speed. The two vehicles met at 276.25 km from Town U. What was the speed of the van in km/h? [4 marks][Answer given: 56 km/h]

Hi
Hope this helps

From 2115 to 2245
Time ------1.5 h

Distance travelled by car from Town U ------- 1.5*85 ------- 127.5km
Distance travelled by van ------- 374.25 – 276.25 ------- 98km
Distance travelled by car from 2245 --------- 276.25 – 127.5 -----148.75km

Time taken ------ 148.75/85 ----- 1.75h

Therefore speed of van ------98/1.75 ---- 56km/h

Best wishes

[tianzhu]

Henry Park P6 Prelim 2010 Paper 2

Q13: A car left City A for City B at 8 am travelling at an average speed of 60 km/h. One hour later, a bus started its journey from City B for City A. At 11.30 am, the two vehicles were 35 km apart after passing each other earlier. If the car reached City B at 1 pm, at what time would the bus arrive at City A?[4 marks][Answer given: 3 pm]

Hi
Hope this helps.

For speed question, it’s important to start with a diagram

From 8am to 9am, the car travelled 60km

From 1130am to 1pm, the car travelled 1.5*60 ----90km

Distance moved by van from 9am to 11.30am ------90+35 ---125km
Therefore van’s speed ---125/2.5 ---- 50km/h

From 9am to 11.30am, the car moved 150km

Distance between city A and city B ----- 60+150+90 -----300km

Time taken by van -------300/50 ------6h
The van arrived at 3pm

Best wishes

[moomoo7368]

Hi vanilla cake, where can we get the prelim papers that you listed?


If there is no centralised place, would any parents with p6 children from those schools be interested in swapping? I’ve got the prelim paper from nanyang.

[tianzhu]

River Valley Primary School P6 Prelim 2010 P2

Q16: A rabbit and a tortoise competed in a 5.2 km race. The rabbit ran at a speed of 20 km/h while the tortoise’s speed was 3 km/h. The tortoise ran continuously to complete the race. However the rabbit ran for 1 min and rested for 20 min. It ran the next 2 min and rested or 20 min. It then ran for the next 3 min and rested for 20 min and so forth. At this rate, how many minutes more would it take the rabbit than the tortoise to complete the race? [5 marks][Answer given: 11.6 min]

Hi VC

I have 1.6min instead of 11.6min.
I'll try tomorrow .

Good night

Best wishes

[Vanilla Cake]

moomoo7368:

Hi vanilla cake, where can we get the prelim papers that you listed?


If there is no centralised place, would any parents with p6 children from those schools be interested in swapping? I've got the prelim paper from nanyang.

Hi moomoo7368,
Pls refer to these http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=4105&start=90 and http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=6459&start=330 for the name of supplier for top papers (Jeremy - 90216478/98518229 )and his contact, location of the stalls selling them, price of these top papers.Just is a summary of the location of these stalls based on feedback from KSP members:

1. Bras Basah Complex - a number of shops are selling.
2. Near Hougang plaza - Blk 804 (not 100% sure), ground floor
3. Near Kovan MRT station - near DBS bank
4. Toa Payoh Central, next to KFC, near MRT, near an Indian Bank, at the
corner.
5. Thomson Plaza to purchase the papers, unit no 01-10, is located next to the Four Leaves bread shop, near to Popular book shop.
6. Tampines Mart - Sam 93397910.
7. Bukit Merah Centre (Outside NTUC)
8. Peace Center
9. Marine Parade

English/Maths/Science
1. Raffles Girls' Primary School
2. Singapore Hokkien Huay Kuan - 5-school combined: Tao Nan, AI Tong, Chongfu, Nan Chiau and Kong Hwa
3. CHIJ St Nicholas Girls' School (Primary)
4. River Valley Primary School
5. Nanyang Primary School
6. Maha Bodhi School
7. Rosyth School
8. Pei Chun Public School
9. Red Swastika School
10. Henry Park Primary School

Chinese
First to ninth school same as above.10th school - Henry Park replaced by Nan Hua.

Thanks.

[Vanilla Cake]

tianzhu:

River Valley Primary School P6 Prelim 2010 P2

Q16: A rabbit and a tortoise competed in a 5.2 km race. The rabbit ran at a speed of 20 km/h while the tortoise’s speed was 3 km/h. The tortoise ran continuously to complete the race. However the rabbit ran for 1 min and rested for 20 min. It ran the next 2 min and rested or 20 min. It then ran for the next 3 min and rested for 20 min and so forth. At this rate, how many minutes more would it take the rabbit than the tortoise to complete the race? [5 marks][Answer given: 11.6 min]

Hi VC

I have 1.6min instead of 11.6min.
I'll try tomorrow .

Good night

Best wishes

Hi Uncle Tianzhu,

Thks for your hard work. Accordingly to the answer sheet given:
16. 115.6-104 = 11.6 min

I have not gone through all the questions yet. So, I am not sure whether the given answer is correct or not. Good night and sleep well.
Best wishes.