Q&A - P5 Math

[MathIzzzFun]

2Transformer:

Please help on the following questions:-


1. Mr. Yong gave $840 of his salary to his mother and gave 1/5 of his remaining salary to his wife. If he had 1/3 of his salary left, how much was his salary?

Remainder --> 5 units
wife --> 1 unit
Left --> 4 units = 1/3 of salary
salary --> 12 units

12 units - 5 units = 7 units --> $840
1 unit --> $ 120

salary --> 12 x $120 = $ 1440

cheers.

[MathIzzzFun]

2Transformer:

Please help on the following questions:-


2. Robert wanted to buy 12 erasers but he found that he was short of $0.80. If he bought 8 erasers, he would have $1.60 left over. How much money did Robert have?

http://i39.tinypic.com/vqieps.png\">

4 erasers --> $ 1.60 + $0.80 = $ 2.40

1 eraser --> $ 0.60

Robert's money --> 8 x $ 0.60 + $ 1.60 = $ 6.40

cheers.

[MathIzzzFun]

2Transformer:

Please help on the following questions:-


3. There were 3/4 as many students in Camp A than in Camp B. After 25 pupils joined Camp B, the ratio of the number of students in Camp B to Camp A becomes 7:4. Find the number of students in Camp B at first.

The number of students in Camp A remained the same, so make the ratio part for Camp A the same in the \"start\" and \"end\" ratios.

At first, students in Camp A : Camp B = 3 : 4 --> 12u : 16u
In the end, students in Camp A : Camp B --> 4 : 7 --> 12u : 21u

Increase in number of students in Camp B = 21u - 16u = 5u

5u --> 25
1u --> 5

At first, number of students in Camp B --> 16 x 5 = 80

cheers.

[cookieandmonster]

Please help with this question:


Peter had 632 stamps and Freddy had 80 stamps. After their father had given them each an equal number of stamps, Peter had 5 times as many stamps as Freddy. How many stamps did their father give to each of them?

[Oldschool]

cookieandmonster:

Please help with this question:


Peter had 632 stamps and Freddy had 80 stamps. After their father had given them each an equal number of stamps, Peter had 5 times as many stamps as Freddy. How many stamps did their father give to each of them?

Hi,

Father gave each of them U stamps, so

632 + U = 5(80 + U)
632 + U = 400 + 5U
U = 58

Regards

[2Transformer]

MathIzzzFun:

2Transformer:

Please help on the following questions:-


1. Mr. Yong gave $840 of his salary to his mother and gave 1/5 of his remaining salary to his wife. If he had 1/3 of his salary left, how much was his salary?

Remainder --> 5 units
wife --> 1 unit
Left --> 4 units = 1/3 of salary
salary --> 12 units

12 units - 5 units = 7 units --> $840
1 unit --> $ 120

salary --> 12 x $120 = $ 1440

cheers.

:thankyou: MathIzzzFun !! My son likes ALL your explaination.

[2Transformer]

MathIzzzFun:

2Transformer:

Please help on the following questions:-


2. Robert wanted to buy 12 erasers but he found that he was short of $0.80. If he bought 8 erasers, he would have $1.60 left over. How much money did Robert have?

http://i39.tinypic.com/vqieps.png\">

4 erasers --> $ 1.60 + $0.80 = $ 2.40

1 eraser --> $ 0.60

Robert's money --> 8 x $ 0.60 + $ 1.60 = $ 6.40

cheers.

:thankyou:

[2Transformer]

MathIzzzFun:

2Transformer:

Please help on the following questions:-


3. There were 3/4 as many students in Camp A than in Camp B. After 25 pupils joined Camp B, the ratio of the number of students in Camp B to Camp A becomes 7:4. Find the number of students in Camp B at first.

The number of students in Camp A remained the same, so make the ratio part for Camp A the same in the \"start\" and \"end\" ratios.

At first, students in Camp A : Camp B = 3 : 4 --> 12u : 16u
In the end, students in Camp A : Camp B --> 4 : 7 --> 12u : 21u

Increase in number of students in Camp B = 21u - 16u = 5u

5u --> 25
1u --> 5

At first, number of students in Camp B --> 16 x 5 = 80

cheers.

:thankyou: MathIzzzFun, thank you for your detailed n yet simple explaination. I really appreciate it.

[MathIzzzFun]

cookieandmonster:

Please help with this question:


Peter had 632 stamps and Freddy had 80 stamps. After their father had given them each an equal number of stamps, Peter had 5 times as many stamps as Freddy. How many stamps did their father give to each of them?

key concept --> difference/gap remains the same...

when same quantity/amount is added/removed from two identities, the difference between the two identities will remain the same ...

http://i40.tinypic.com/i2u68g.png\">

Peter had 632 stamps and Freddy had 80 stamps. After their father had given them each an equal number of stamps, Peter had 5 times as many stamps as Freddy. How many stamps did their father give to each of them?

At first,
Peter -> 632 stamps
Freddy --> 80 stamps
632 - 80 = 552 --> Peter had 552 more stamps then Freddy

In the end,
Peter --> 5 units
Freddy --> 1 unit

5 units - 1 unit = 4 units

since both received the same number of stamps from their father, Peter will still have 552 more stamps than Freddy in the end,

4 units --> 552
1 unit --> 138

Number of stamps each received --> 138 - 80 = 58

cheers.

[MathIzzzFun]

2Transformer:

MathIzzzFun:

[quote=\"2Transformer\"]Please help on the following questions:-


1. Mr. Yong gave $840 of his salary to his mother and gave 1/5 of his remaining salary to his wife. If he had 1/3 of his salary left, how much was his salary?

Remainder --> 5 units
wife --> 1 unit
Left --> 4 units = 1/3 of salary
salary --> 12 units

12 units - 5 units = 7 units --> $840
1 unit --> $ 120

salary --> 12 x $120 = $ 1440

cheers.

:thankyou: MathIzzzFun !! My son likes ALL your explaination.[/quote]glad to be of help .. cheers!