Tutor MathsGuru: Ask me for your burning Maths questions!

[KSP]

i thought thread this is a Pri level maths??

[babydragon]

Hi

I have a physics question which i do not understand. If you know, please help.
three conducting balls, X, Y and Z are suspended vertically, side by side, without touching each other, by light insulating threads. X is charged positively. Y is negatively charged. Z is positively charged.
The following procedures are carried out:
1> Z is earthed and the earthing connection is then removed.
2> Y&Z are brought into contact and then separated
3> X&Y are brought into contact and then separated.
What is the resulting charges on Y & Z?

[kwcllf]

Hi,


Please help with the following question. Thanks!

9 oranges cost $11.00.
James bought a total of 1000 apples and oranges for $999.00.
How many apples and how many oranges did he buy?

[archie2]

babydragon:

Hi

I have a physics question which i do not understand. If you know, please help.
three conducting balls, X, Y and Z are suspended vertically, side by side, without touching each other, by light insulating threads. X is charged positively. Y is negatively charged. Z is positively charged.
The following procedures are carried out:
1> Z is earthed and the earthing connection is then removed.
2> Y&Z are brought into contact and then separated
3> X&Y are brought into contact and then separated.
What is the resulting charges on Y & Z?

Hi babydragon
1>>When Z is earthed, free electron will flows from earth to the positively charged balls --> neutralising it.
2>>Next, when Y&Z are in contact, -ve charged from ball Y will flows into ball Z. When separated, both balls Y & Z will be negatively charged.
3>>Then, when balls X&Y are in contact, +ve & -ve will neutralise each other. Assuming all balls have equal number of -ve or +ve charge initially, then ball X will have more +ve charge while ball Y has less negative charge. The +ve charge from ball X will neutralise the -ve charged in ball Y. In the end, there will be more +ve charge balance and both balls will be positively charged.
Therefore the resulting charge in ball Y is +ve and ball Z is -ve.
Hope this help

[MathIzzzFun]

kwcllf:

Hi,


Please help with the following question. Thanks!

9 oranges cost $11.00.
James bought a total of 1000 apples and oranges for $999.00.
How many apples and how many oranges did he buy?

Hi

apples cost ?

cheers.

[kwcllf]

Hi please help with the following question.


Dolly had 80 more stickers than Jenny. Dolly gave 25% of her stickers to Jenny. Jenny in return gave 60% of her stickers to Dolly. In the end, Dolly had 100 stickers more than Jenny. How many stickers did Dolly have at first.

Thanks!

[MathIzzzFun]

kwcllf:

Hi please help with the following question.


Dolly had 80 more stickers than Jenny. Dolly gave 25% of her stickers to Jenny. Jenny in return gave 60% of her stickers to Dolly. In the end, Dolly had 100 stickers more than Jenny. How many stickers did Dolly have at first.

Thanks!

Hi

there are a few methods.. eg using units, model.

At first,
Jenny -> 4 units
Dolly -> 4 units + 80

After Dolly gave 25% ie 1 unit + 20, to Jenny :
Jenny -> 5 units + 20
Dolly -> 3 units + 60

After Jenny gave 60% (3/5) ie 3 units + 12 to Dolly :
Jenny -> 2 units + 8
Dolly -> 6 units + 72

In the end Dolly had 100 more than Jenny:
So, 6 units + 72 = 2 units + 8 + 100
--> 4 units = 108 - 72 = 36, 1 unit --> 9

At first, Dolly had 4 units + 80 --> 116 stickers.

cheers.

[kwcllf]

Thanks again!


I need help on another question.

Jan and Kay had equal number of sweets and chocolate. Jan ate 12 sweets and Kay ate 18 chocolates and ten the ratio of Jan’s sweets to chocolate became 1:7 and the ratio of Kay’s sweets to chocolate became 1:4. How many sweets did Jan have at first?

Thanks!

[MathIzzzFun]

kwcllf:

Thanks again!


I need help on another question.

Jan and Kay had equal number of sweets and chocolate. Jan ate 12 sweets and Kay ate 18 chocolates and ten the ratio of Jan's sweets to chocolate became 1:7 and the ratio of Kay's sweets to chocolate became 1:4. How many sweets did Jan have at first?

Thanks!

hi

u r welcome.

There many examples of similar questions in the forum - you may want to check out the P5 maths/P6 maths threads for the solutions first. Let me know if you still can't sort it out.

cheers.

[kwcllf]

kwcllf:

Thanks again!


Jan and Kay had equal number of sweets and chocolate. Jan ate 12 sweets and Kay ate 18 chocolates and ten the ratio of Jan's sweets to chocolate became 1:7 and the ratio of Kay's sweets to chocolate became 1:4. How many sweets did Jan have at first?

Hi MathIzzzFun,

Not sure if I get this correct.

Jan - 1 : 7 (after eating 12 sweets) ------> (x 4) ------> 4 : 28
Kay - 1 : 4 (after eating 18 chocolates) --> (x 7) ------> 7 : 28

7u - 4u = 3u

3u = 12 sweets
1u = 4 sweets

Therefore, Jan at first has (4u x 4) + 12 sweets = 16 + 12 = 28 sweets