Q&A - P4 Math

[MathIzzzFun]

[quote=\"Bunny27\"]Hi my nephew needs help in this question:

Mrs lim bought 2 mangoes and 3 peaches for $14.85 altogether. A mango cost 3times as much as a peach. Find the cost of 1 mango.

Thanks


Hi

http://i51.tinypic.com/8yuzj8.jpg\">

cheers.

[trileets]

Hi, anyone can help me with this?


Ahmad has $40 more than Ben. After giving 1/5 of his money to Ben, Ben now has 7/8 of what Ahmad has. How much did they have?

Thanks a million!

[MathIzzzFun]

trileets:

Hi, anyone can help me with this?


Ahmad has $40 more than Ben. After giving 1/5 of his money to Ben, Ben now has 7/8 of what Ahmad has. How much did they have?

Thanks a million!

Hi

http://i53.tinypic.com/16ghlp5.jpg\">

cheers.

[thmejlfm]

Please help.


In a group of children, the mean age of the children is 10 years. If the mean age of the 8 boys was 15 years, the mean age of the girls was6 years. How many children were there altogether?

[thmejlfm]

2nd question.


44 boys and 47 girls want to school camp. The pupils were put into groups. There was an equal no. Of pupils in each group.
A) how many groups were there?

In each group, the no of boys was 1 more or1 less than the no of girls,
B) how many groups had more girls than boys?

[MathIzzzFun]

thmejlfm:

Please help.


In a group of children, the mean age of the children is 10 years. If the mean age of the 8 boys was 15 years, the mean age of the girls was6 years. How many children were there altogether?

Hi

Total excess above average = Total shortfall below average.

8 x (15-10) = N x (10-6)
N= 10 --> 10 girls, total 10 + 8 = 18 children.

cheers.

[MathIzzzFun]

thmejlfm:

2nd question.


44 boys and 47 girls want to school camp. The pupils were put into groups. There was an equal no. Of pupils in each group.
A) how many groups were there?

In each group, the no of boys was 1 more or1 less than the no of girls,
B) how many groups had more girls than boys?

Hi

some information is missing.. for eg. For A) it can be either 7 groups of 13 children or 13 groups of 7 children

B) For 13 groups with 7 children each, each group will have either 4 boys/3 girls or 3 boys/4 girls

44 boys --> 44/13 = 3R5. So, there are 5 groups with 4 boys/3 girls and 8 groups with 3 boys/4 girls ie 8 groups with more girls.

For 7 groups with 13 children each, each group will have either 7 boys/6 girls or 6 boys/7 girls.

44 boys --> 44/7 = 6R2. So, there are 2 groups with 7 boys/6 girls and 5 groups with 6 boys/7 girls ie 5 groups with more girls.

cheers.

[thmejlfm]

Hi, thanks for the reply.


One of friends told my dd, was

8 x 15 = 120 (boys total)
G x 6 = 6G (girls total)

120 + 6G/8+G = 10
120 + 6G = 80 + 8G
40 =2G
G = 20

So, total children = 28.

So, which one is correct?

MathIzzzFun:

thmejlfm:

Please help.

In a group of children, the mean age of the children is 10 years. If the mean age of the 8 boys was 15 years, the mean age of the girls was6 years. How many children were there altogether?

Hi

Total excess above average = Total shortfall below average.

8 x (15-10) = N x (10-6)
N= 10 --> 10 girls, total 10 + 8 = 18 children.

cheers.

[atutor2001]

thmejlfm:

Hi, thanks for the reply.


One of friends told my dd, was

8 x 15 = 120 (boys total)
G x 6 = 6G (girls total)

120 + 6G/8+G = 10
120 + 6G = 80 + 8G
40 =2G
G = 20

So, total children = 28.

So, which one is correct?

MathIzzzFun:

[quote=\"thmejlfm\"]Please help.

In a group of children, the mean age of the children is 10 years. If the mean age of the 8 boys was 15 years, the mean age of the girls was6 years. How many children were there altogether?

Hi

Total excess above average = Total shortfall below average.

8 x (15-10) = N x (10-6)
N= 10 --> 10 girls, total 10 + 8 = 18 children.

cheers.

[/quote]Both methods are correct. But your friend made calculation error :

(120 + 6G)/(8+G) = 10
120 + 6G = 80 + 8G (wrong)
Should be 120 + 6G = 80 + 10G
40 =4G
G = 10

So, total children = 18.

[thmejlfm]

Ok. Thanks


\"]

thmejlfm:

Hi, thanks for the reply.

One of friends told my dd, was

8 x 15 = 120 (boys total)
G x 6 = 6G (girls total)

120 + 6G/8+G = 10
120 + 6G = 80 + 8G
40 =2G
G = 20

So, total children = 28.

So, which one is correct?

MathIzzzFun:

[quote=\"thmejlfm\"]Please help.

In a group of children, the mean age of the children is 10 years. If the mean age of the 8 boys was 15 years, the mean age of the girls was6 years. How many children were there altogether?

Hi

Total excess above average = Total shortfall below average.

8 x (15-10) = N x (10-6)
N= 10 --> 10 girls, total 10 + 8 = 18 children.

cheers.

[/quote]Both methods are correct. But your friend made calculation error :

(120 + 6G)/(8+G) = 10
120 + 6G = 80 + 8G (wrong)
Should be 120 + 6G = 80 + 10G
40 =4G
G = 10

So, total children = 18.[/quote]