Q&A - PSLE Math

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!



2. Jin walked from home to school. For the first 2 minutes, he was walking at an average speed of 40m/min. When he realised that he was going to be late by 3 minutes, he quickly inceased his speed by 10m/min. As a result, he was early by 1 minute. Find the distance between his home to his school.

Q2.
increased speed = 40m/min + 10m/min = 50m/min
original speed: increased speed = 40 : 50 = 4:5

ratio of time taken to reach school for the 2nd part of the journey at original speed : increased speed = 5units : 4units

Time taken to reach the school at increased speed is (3+1)= 4 min faster than at original speed
1 unit = 4 min, 5 units = 20 min
Distance to school = (20+2)x40 = 880 m.

cheers.

[MathIzzzFun]

Spongy:

Hi I need help thank you very much!


1. Ann, Ben and Cindy had a total of 640 sweets. The ratio of Ben's sweets to Cindy's sweet was 5:4 at first. After Ann and Ben each gave 1/2 of their sweets away, the three children had 420 sweets left. How many sweets did Ann have at first?

Q1.
Total number of sweets given away by Ann & Ben = 640 - 420 = 220
Total number of sweets Ann & Ben had at first = 220 x 2 = 440
Number of sweets Cindy had = 640 - 440 = 200
Number of sweets Ben had at first = 5 * 200/4 = 250
Number of sweets Ann had at first = 440 - 250 = 190

cheers.

[Flipper123]

Thanks Cinman for helping with the rombus question. I think this is too difficult for a p6 student. Sigh…

[cimman]

Flipper123:

Thanks Cinman for helping with the rombus question. I think this is too difficult for a p6 student. Sigh...

here is another way of viewing it. In general, whenever you see a symmetrical shape, try to cut it along it's lines of symmetry. In most problems, equilateral triangles are divided into 3 symmetrical shapes.
http://i48.tinypic.com/29lo0hc.png\">
From the above, you'll see that the smaller rhombus now consists of 2 triangles.

[tianzhu]

Michaelia0816:

Hey, I not sure,pls help pls

Hi girl

Please post the picture of the prism.

Best wishes

[Michaelia0816]

Never mind, it just a picture of a triangle prism

[Michaelia0816]

Pls help, I really don't know, pls also help with the other 11 questions. :?:


1. 10 workers can complete a painting job. If there are 2 more workers, the painting job will be completed 6 days sooner. If the same painting job were to be done 21 days earlier, how many additional workers are needed?

[Michaelia0816]

2. 173 sweets are to be given to 8 kids in as fair manner as possible. What is the maximum number of sweets a kid can get?

[Michaelia0816]

3. 2 candles of the equal length are lit at the same time. One candle took 5 hours to burn out and the other 2.5 hour. After how long will the length of the faster burning candle be 4/7 of the slower burning one?

[Michaelia0816]

4. 2 groups of people , A and B are working on a project. If 18 people move from group A to group B, then group B will have 3 more people than group A. If we take away 18 people from both groups, then the remaining people in group B is 5/8 of that of group A. Find the number of people in each group at first.