Q&A - P5 Math

[MathIzzzFun]

imacsg:

Yazid and his class raced one another across a field. Midway through the race, 1/5 of Yazid's classmates was running in front of him and 7/9 of the total number of pupils in the class was running behind him. What was the total number of pupils in the class including Yazid?


Can anyone solve the above question? Thanks

Total number in class --> 9u
Pupils in front --> 2u-1, class mates --> 9u-1
so, 2u -1 : 9u-1 = 1 : 5
cross multiply/equalize:
10u-5 = 9u-1
1u--> 4
total number in class --> 36
cheers.

[imacsg]

MathIzzzFun,

Thanks, I also have 45 as the ans.
But the ans is 36, I think the ans is wrong.

[MathIzzzFun]

imacsg:

MathIzzzFun,

Thanks, I also have 45 as the ans.
But the ans is 36, I think the ans is wrong.

oops..I read the question as 1/5 of class in front and 7/9 of class behind --> should be 1/5 of classmates (ie total number -1) in front and 7/9 class behind

Total number in class --> 9u
Pupils in front --> 2u-1, class mates --> 9u-1
so, 2u -1 : 9u-1 = 1 : 5
cross multiply/equalize:
10u-5 = 9u-1
1u--> 4
total number in class --> 36

cheers.

[imacsg]

Hi MathIzzzFun,

You are sharp, I also did not notice that. Thanks

[MathIzzzFun]

imacsg:

Hi MathIzzzFun,

You are shape, I also did not notice that. Thanks

solution using MD..


http://i48.tinypic.com/33dfplz.png\">

cheers.

[Udon]

MathIzzzFun:

Udon:

Please help to explain the answer provided for this Question...Thanks.


Q1. What is the maximum number of wooden blocks measuring 0.03m by 0.02m by 0.06m that can be cut from a big block of wood measuring 12 cm by 11 cm by 15 cm？

Given answer:-

0.03m x 100 = 3 cm
0.02m x 100 = 2 cm
0.06m x 100 = 6cm

12 divided by 6 = 2
why 12/6, why not the \"length / length and the breadth / breadth and the height / height manner? :?:

11 divided by 2 = 5 R 1
15 divided by 3 = 5

2 x 5 x 5 = 50
The maximum number of wooden blocks that can be cut is 50.


Best Regards
Udon

Maximum number of blocks that can be cut is 54

http://i47.tinypic.com/1251jeq.png\">

cheers.

Thank you very much for your help, think the child wont be able to visualize but I believed some children they can...

[terilyn]

Appreciate your help to solve these questions from Henry Park 2011:


Q7. Cheryl and Serene have some money. If Cheryl gives Serene $20, they will have the same amount of money. If Serene gives Cheryl $25, Cheryl will have twice as much money as Serene. How much money does Serene have.

http://i49.tinypic.com/98bqz4.jpg\">

[tianzhu]

terilyn:

Appreciate your help to solve these questions from Henry Park 2011:

Q7. Cheryl and Serene have some money. If Cheryl gives Serene $20, they will have the same amount of money. If Serene gives Cheryl $25, Cheryl will have twice as much money as Serene. How much money does Serene have.

Hi

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8034/8022550020_fcd7227393_z.jpg\">

[tianzhu]

Hi


For the second question

Triangle

Shaded : unshaded ------ 2:3 (5)

Rectangle

Shaded : unshaded ------ 2:13 (15)

Fraction of whole figure is unshaded ------ (13+3)/(13+3+2) --------- 16/18 -------- 8/9

Best wishes

[YumYum]

Hi, need help with this Qn:


Henry has some 10-cent, 20-cent and 50-cent coins. The ratio of the number of 10-cent coins to the number of 20-cent coins is 7:2. The number of 50 cents coins is 1/2 the number of 20-cent coins. The total value of the 10-cent coins is $16 more than the total value of 50-cent coins. How much does Henry have altogether?

Thanks.