Q&A - PSLE Math
-
Michaelia0816:
HiDear Tianzhu and friends here,
I have 24 question left, and was not sure of the question so I am going to post the 24 question soon?
1) Mr Koh drove from his home to the airport and back? The distance between his home ad the airport was 60km. He covered the forward journey at 42km/h and return at 56km/h. What was his average speed for the entire journey?
Speed ----- 42 km/h
Time taken ------- 60/42 ------ 10/7 h ------20/14 h
Speed ----- 56 km/h
Time taken ------- 60/56 -------- 15/14 h
Total time taken -------- 35/14 h
Average speed for entire journey -------- 120/(35/14) ------- 48km/h
Best wishes -
Michaelia0816:
Hi2) Ali set off from Town P for Town Q at 8.30am. 30 minutes later, Jim set off from Town Q for Town P along the road as Ali. Ali and Jim were travelling at constant speed of 60km/h and 50km/h respectively. At noon, they were 220km apart?
A) How far from Town P would they pass each other?
B) At what time would they pass each other?
Start with a simple diagram.
In 30 minutes, Ali covered ½*60 ----- 30 km
In 1 h, Ali and Jim covered 110km (60+50)
220/110 ------ 2 h
From 9am to noon ----- (3h)
In 5h, Ali covered 60*5 ------ 300 km
They passed one another at a distance of (30+330) or 330 km from P.
They would pass one another at 2 pm (2h from noon).
Best wishes -
Michaelia0816:
3) Mike and Alex started cycling at 9.15 am and 9.30 am respectively. They started off from the same location but in opposite directions along a straight road. By 11 am, they were 80km apart? If Mike was cycling at an average speed of 20km/h, find the average speed of Alex?
Hi
Start with a simple diagram
From 9.15 am to 11 am --------- 1h 45 minutes or 1.75h
Mike covered 1.75*20 ------- 35 km
Alex covered (80-35) ------- 45 km from 9.30 am to 11 am.
Alex’s average speed ------- 45/1.5 ------- 30 km/h
Best wishes -
Appreciate any help to solve this qn in PSLE bk qn11.
A B C D
1 2 3 4
8 7 6 5
9 10 11 12
16 15 14 13
In which column will the number 432 appear?
Soln given is:
Groups of 8 in a pattern, 2 rows in a group.
432/8=54 groups
54 groups of 8 = 432
Ans: 432 can be found in row 108 column A.
Not able to understand the above soln and/or is there another mtd? Thanks:) -
Michaelia0816:
Hi4) Town J and Town K were 450km apart. Nancy started to drive from Town J for Town K at 10am. At hour later, Jenny started to drive from Town K for Town J at 75% the average speed of Nancy. they met each other at 1pm along the way.
A) at what speed was nancy driving?
b) How far from Town J did they met each other?
Start with a simple diagram.
In 1h, Nancy covered 4 units.
In 1h, Jenny covered 3 units.
From 10 am to 11 am, Nancy covered 4 units.
From 11 am to 1 pm, Nancy covered 8 units and Jenny covered 6 units
Total units ------- 18 units
450/18 ------25
4 units ------ 4*25 ------ 100 km/h (Nancy’s speed)
They met at 100+200 or 300 km away from J.
Best wishes -
Hi help needed!
A tank was half filled with water. More water was added until it was 2/3 full. The ratio of the mass of the tank when it was 1/2 full to the mass of the tank when it was 2/3 full was 7:9.
a) What is the ratio of the volume of water in the tank when it was 1/2 full to the volume of the water went he tank was 2/3 full?
b) the mass of the empty tank was 500g. What was the total mass of the tank and water when the tank was 2/3 full? -
Michaelia0816:
Hi5) At 10am, Wang set off from Town A for Town B at an average speed of 64 km/h. at the same time, Han set off from Town B for Town A at an speed 25% faster than Wang. they were 144 km apart after 2/3/4 h.
A) How far apart were the two towns?
B) At what time would they pass each other along the way?
Han’s speed ------ 64*1.25 ------- 80 km/h
In 1 h, Wang and Han covered (64 + 80) ------- 144 km
In 2.75h, they covered (2.75*144) ------ 396 Km
Distance between two towns ------ 396 + 144 ------ 540 km
They met at (2.75+1) or 3.75h from 10 am which is 1.45 pm
Best wishes -
Michaelia0816:
HiEd set off from his home for Town Q at 11.20 am . by 1 pm, he had covered 2/5 of the journey aft travelling at an average speed of 60km/h. After that, he increased his speed by 20% for the rest of the journey.
A) what was the distance from Ed home to town Q?
B) At what time did Ed arrived in Town Q
From 1120 am to 1pm -------- 1h 40 mins
He covered (60*5/3 ) -------- 100km
2 units------ 100 km
5 units ------- 250 km (Distance from Ed’s home to Q)
Increased speed ------- 72 km/h
150/72 ------ 2h 5 mins
Ed arrived in Town Q at 3.05 pm
Best wishes -
Michaelia0816:
9)A motorist took 3 h to travel from p to r while a cyclist took 5h20min to travel from s to q. If both of them set off at the same time, how far away from p did they pass by each other?
Hi
Please confirm.
Best wishes -
Michaelia0816:
HiRoger took 1/1/3 h to drive from Greenland to pinkcity at an average speedof 0km/h. After this, he increased his speed by 25% and continued driving to redsville for 40 minutes.
A) how far did Roger drive together?
B) find his average speed for the whole journey?
Please check.
Best wishes
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login