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[maths6a]

Hi Can anyone help with this question?

How many 3-digit number combinations are there on a 3-digit number lock if all the 3-digits used are different and the numbers are greater than 800?

Thanks.

[Dharma]

maths6a:

Hi Can anyone help with this question?

How many 3-digit number combinations are there on a 3-digit number lock if all the 3-digits used are different and the numbers are greater than 800?

Thanks.

Digit in hundreds place => 8 or 9
Digit in tens place => 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9
Digit in ones place => 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9

Since the 3 digits used are different, you have 2 choices for hundreds place, 9 choices for tens place(1 choice already selected for 100s place) and 8 choices for the ones place (2 choices already chosen for 100s and 10s place)

No. of combinations = 2 x 9 x 8 = 144

[livewith_vanilla]

Dharma:

livewith_vanilla:

Hi Superstar,


Your questions seem to come from Henry Park Preliminary Paper 2 2009.

The solution for Q14 as stated on the answer key is:

105%G+90% G+18=408
195%G+18=408
100%G=390/195x100=200
200x2+20=420
420x8=3360

Ans: $3360

For reference, the question is as of below:

Cinema admission tickets for children were priced at $8 each.there were 20 more than girls inthe cinema for the movie. For the second movie ,the number of boys decreased by 10% but the number of girls increased by 5%.if there were 408 children at the second movie, how much money was collected from the sales of admission ticket for the first movie?

For Q15, the answer key did not provide any solutions. But I'm able to solve (A). The answers are (a)5:1 and (b)150

For reference, the question is as of below:
A librarian counted the number of adults in the library and found that 2/5 of the number of women was equal to 2 times the number of men.when another 12 men entered the library and 45 women left the library, the ratio of the number of women to the number of men became 5:2.

(A) what was the ratio of the number of women at first to the number of men at first?give youir answer in its simplest form.

(B)find the number of women in the library at first.

2/5W=2 M
1/5W=1 M

W:M
5:1

Ans: 5:1

However, I am too unable to solve (B). The answer I got was 105 and not 150. Thus my apologies.

Are you a primary 6 student or a parent?

Hi superstar and livewith_vanilla,

Hope this helps.

At first
Ratio => Women : Men = 5 : 1

At last
Ratio => Women : Men = 5u - 45 : 1u + 12 = 5 : 2

10u – 90 = 5u + 60
5u = 150
1u = 30

No. of women at first = 5u = 5 x 30 = 150

My solutions are similar, just stucked at the last statement.

[super star]

Hi livewith_vanilla

Thank you very much
Iam a parent who is studying p6 :lol:
please explain how u got 105%G+90% G+18=408
I cannot understand what how u got 90%G+18

livewith_vanilla:

Hi Superstar,

Your questions seem to come from Henry Park Preliminary Paper 2 2009.

The solution for Q14 as stated on the answer key is:

105%G+90% G+18=408
195%G+18=408
100%G=390/195x100=200
200x2+20=420
420x8=3360

Ans: $3360

For reference, the question is as of below:

Cinema admission tickets for children were priced at $8 each.there were 20 more than girls inthe cinema for the movie. For the second movie ,the number of boys decreased by 10% but the number of girls increased by 5%.if there were 408 children at the second movie, how much money was collected from the sales of admission ticket for the first movie?

For Q15, the answer key did not provide any solutions. But I'm able to solve (A). The answers are (a)5:1 and (b)150

For reference, the question is as of below:
A librarian counted the number of adults in the library and found that 2/5 of the number of women was equal to 2 times the number of men.when another 12 men entered the library and 45 women left the library, the ratio of the number of women to the number of men became 5:2.

(A) what was the ratio of the number of women at first to the number of men at first?give youir answer in its simplest form.

(B)find the number of women in the library at first.

2/5W=2 M
1/5W=1 M

W:M
5:1

Ans: 5:1

However, I am too unable to solve (B). The answer I got was 105 and not 150. Thus my apologies.

Are you a primary 6 student or a parent?

[super star]

thanks Dharma

Dharma:

livewith_vanilla:

Hi Superstar,


Your questions seem to come from Henry Park Preliminary Paper 2 2009.

The solution for Q14 as stated on the answer key is:

105%G+90% G+18=408
195%G+18=408
100%G=390/195x100=200
200x2+20=420
420x8=3360

Ans: $3360

For reference, the question is as of below:

Cinema admission tickets for children were priced at $8 each.there were 20 more than girls inthe cinema for the movie. For the second movie ,the number of boys decreased by 10% but the number of girls increased by 5%.if there were 408 children at the second movie, how much money was collected from the sales of admission ticket for the first movie?

For Q15, the answer key did not provide any solutions. But I'm able to solve (A). The answers are (a)5:1 and (b)150

For reference, the question is as of below:
A librarian counted the number of adults in the library and found that 2/5 of the number of women was equal to 2 times the number of men.when another 12 men entered the library and 45 women left the library, the ratio of the number of women to the number of men became 5:2.

(A) what was the ratio of the number of women at first to the number of men at first?give youir answer in its simplest form.

(B)find the number of women in the library at first.

2/5W=2 M
1/5W=1 M

W:M
5:1

Ans: 5:1

However, I am too unable to solve (B). The answer I got was 105 and not 150. Thus my apologies.

Are you a primary 6 student or a parent?

Hi superstar and livewith_vanilla,

Hope this helps.

At first
Ratio => Women : Men = 5 : 1

At last
Ratio => Women : Men = 5u - 45 : 1u + 12 = 5 : 2

10u – 90 = 5u + 60
5u = 150
1u = 30

No. of women at first = 5u = 5 x 30 = 150

[livewith_vanilla]

super star:

Hi livewith_vanilla

Thank you very much
Iam a parent who is studying p6 :lol:
please explain how u got 105%G+90% G+18=408
I cannot understand what how u got 90%G+18

livewith_vanilla:

Hi Superstar,

Your questions seem to come from Henry Park Preliminary Paper 2 2009.

The solution for Q14 as stated on the answer key is:

105%G+90% G+18=408
195%G+18=408
100%G=390/195x100=200
200x2+20=420
420x8=3360

Ans: $3360

For reference, the question is as of below:

Cinema admission tickets for children were priced at $8 each.there were 20 more than girls inthe cinema for the movie. For the second movie ,the number of boys decreased by 10% but the number of girls increased by 5%.if there were 408 children at the second movie, how much money was collected from the sales of admission ticket for the first movie?

For Q15, the answer key did not provide any solutions. But I'm able to solve (A). The answers are (a)5:1 and (b)150

For reference, the question is as of below:
A librarian counted the number of adults in the library and found that 2/5 of the number of women was equal to 2 times the number of men.when another 12 men entered the library and 45 women left the library, the ratio of the number of women to the number of men became 5:2.

(A) what was the ratio of the number of women at first to the number of men at first?give youir answer in its simplest form.

(B)find the number of women in the library at first.

2/5W=2 M
1/5W=1 M

W:M
5:1

Ans: 5:1

However, I am too unable to solve (B). The answer I got was 105 and not 150. Thus my apologies.

Are you a primary 6 student or a parent?

A parent studying p6? wow

If you draw the model,

You will see that at first,

girls=100%
boys=100%+20

On the second day,

girls increase by 5%, thus the final percentage of girls is 105%.

boys decrease by 10%, this final percentage is 90%+(90/100x20)

[clblinym]

Hi, Parents


Can anyone help solve the following math question. Many thanks.

The answer given is 5:2.

Amy
http://www.postimage.org/image.php?v=aVi95Tr

[catddy2002]

Hi,


How to solve this questions:

1) 3/4 of a cake was cut into 8 pieces. What fraction f the cake is each of the 8 pieces?

1) 1/8
2) 3/8
3) 3/32
4) 29/32 ( )

2) What is twice the sum of 20 hundreths, 5 tenths and 17 ones?

1) 17.25
2) 17.70
3) 222
4) 2022 ( )

[starlight1968sg]

catddy2002:

1) 3/4 of a cake was cut into 8 pieces. What fraction f the cake is each of the 8 pieces?


1) 1/8
2) 3/8
3) 3/32
4) 29/32 ( )

2) What is twice the sum of 20 hundreths, 5 tenths and 17 ones?

1) 17.25
2) 17.70
3) 222
4) 2022 ( )

1) (3/4) / 8 = (3 / 4) * (1 /8 ) = 3/32
2) 20 hundredths = 0.20,
5 tenths = 0.5
17 ones = 17
the sum is 17.7.
Then twice is 17.7 * 2 = ???

[maths6a]

Dharma:

maths6a:

Hi Can anyone help with this question?

How many 3-digit number combinations are there on a 3-digit number lock if all the 3-digits used are different and the numbers are greater than 800?

Thanks.

Digit in hundreds place => 8 or 9
Digit in tens place => 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9
Digit in ones place => 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9

Since the 3 digits used are different, you have 2 choices for hundreds place, 9 choices for tens place(1 choice already selected for 100s place) and 8 choices for the ones place (2 choices already chosen for 100s and 10s place)

No. of combinations = 2 x 9 x 8 = 144

Thanks for your solution. Will study it.