Q&A - P5 Math

[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.

[tianzhu]

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.

Hi

You may use “Number*Value” method.

10-cent -------- 7*10 ------- 70u

20-cent ------- 2*20 ------- 40u

50-cent -------- 1*50 ------ 50u

70 -50 ----- 20

20u ------- 1600

1u ------- 80

Altogether, he had 160*80 ------ $128

Best wishes

[ozora]

need some guide for the following questions.

1) ada and siti had some stamps in the ratio of 3:4.
after Ada bought 5 more stamps and siti gave away 1/5 of her stamps, they had the same number of stamps.
How many stamps did siti give away and what was the total number of stamps for 2 girls at first?



2)there were 1600 participants in a game. 30% were male participants.
when more male participants joined in, the male participants were increased to 60%. How many male participants joined in the contest?
is the answer : 1200 for this question?