Q&A - PSLE Math

[MathIzzzFun]

bobsg01:

P6 problem.


Appreciate your solution and thanks in advance.

http://i56.tinypic.com/2uhpzk5.jpg\">

Hi

ratio of number of 20cent coins to number of 50cent coins
= 7 : 1
= 49u : 7u (multiply by 7 because in the end 2/7 of original number of coins left)

Total 56u
2/7 of coins left = 16u

Number of 50 cents coins spent = 72.50 x 2 = 145
Number of 50 cents coins left = 7u - 145
Number of 20cent coins left = 2/7 x 49u = 14u

total number of coins left = 14u + 7u -145 = 21u -145 = 16u
5u = 145, 1u = 29
Number of 20 cents coins left = 14u = 14 x 29
Amount of 20 cents coins left = 14 x 29 x 0.20 = $81.20
Number of 50 cents coins left = 7u - 145 = 7 x 29 - 145 = 58
Amount of 50 cents coins left = 58 x 0.50 = $29

total amount left = $ 29 + $81.20 = $110.20

cheers.

[MathIzzzFun]

raghupavithra:

4.


WXYZ is a square with each side divided into 3 segments of length 1 cm, 9 cm and 1 cm respectively, as shown in the diagram below. Find the total area of the four shaded triangles. http://i52.tinypic.com/16kw2ug.jpg\">


how to solve this

Hi

\"Join\" the 4 shaded triangles at the centre, and get a square of 9 cm x 9cm = 81 square cm.

cheers.

[bobsg01]

Thanks for the solution MathIzzzFun.

[bobsg01]

Ratio problem.


Thanks for the help.

http://i52.tinypic.com/4lkj9f.jpg\">

[MathIzzzFun]

bobsg01:

Ratio problem.


Thanks for the help.

http://i52.tinypic.com/4lkj9f.jpg\">

Hi

http://www.flickr.com/photos/62167097@N02/5973013872/in/photostream

cheers.

[bobsg01]

Thanks for the solution MathIzzzFun.


Have a query:

Alina = 42 / 7 = 6 units

Adeline = (how to calculate 10 units + 6)

[MathIzzzFun]

bobsg01:

Thanks for the solution MathIzzzFun.


Have a query:

Alina = 42 / 7 = 6 units

Adeline = (how to calculate 10 units + 6)

Hi

Originally, the ratio was 3: 5 = 6U : 10U >> 10U was what Adeline had at first. After she got 6 more, it becomes 10U + 6 and this is equal to 7(U+7)

cheers.

[bobsg01]

IC :yikes:


3: 5 = 6U (3+3) : 10U (5+5)

Thanks for the enlightening MathIzzzFun.

[wkong]

Hi All,


Need help for the following:

Mdm Zhang packed some beads into 14 small boxes and 15 big boxes. There were equal number of beads in each small box and equal number of beads in each big box. 3/8 of the beads were packed in small boxes. How many beads were there in each big box?

Thanks,
wkong

[tianzhu]

wkong:

Hi All,


Need help for the following:

Mdm Zhang packed some beads into 14 small boxes and 15 big boxes. There were equal number of beads in each small box and equal number of beads in each big box. 3/8 of the beads were packed in small boxes. How many beads were there in each big box?

Thanks,
wkong

Hi

This has been discussed in one of the earlier posts.

Please refer to the answer by MathIzzzFun
http://www.flickr.com/photos/62167097@N02/5664739745/in/photostream

Best wishes