Tutor MathsGuru: Ask me for your burning Maths questions!

[underthesea]

Can someone help me with this maths question:


There are 2 boxes. Box and Box Y, both of which contain pens and erasers only. The respective numbers of pens and erasers in Box X are in the ratio 1:3. The respective numbers of pens and erasers in Box Y are in the ratio 5:6. The number of items in Box X is thrice the number of items in Box Y.

(a) Find the ratio of the number of pens in Box Y to the number of pens in Box X.

(b) Knowing that there are 100 more erasers in Box Y than in Box X, find the number of erasers in Box Y.

anything wrong with the question?

TIA

[YLH88]

Hi Mathsguru,


Need your help with the below questions :

1) Doran had 8/11 of the number of game cards Thomas had. After Thomas lost 18 cards to Doran, they both had the same number of cards.

a) How many more game cards did Thomas have than Doran at first ?
b) As the game continued, Doran won more cards from Thomas. How many more cards did Thomas lose to Doran such that Doran has 3 times as many cards as him ?

I’m able to get the answer for (a), which is 36. But can’t find for (b)

Thank you!

[CoffeeCat]

YLH88:

Hi Mathsguru,


Need your help with the below questions :

1) Doran had 8/11 of the number of game cards Thomas had. After Thomas lost 18 cards to Doran, they both had the same number of cards.

a) How many more game cards did Thomas have than Doran at first ?
b) As the game continued, Doran won more cards from Thomas. How many more cards did Thomas lose to Doran such that Doran has 3 times as many cards as him ?

I'm able to get the answer for (a), which is 36. But can't find for (b)

Thank you!

draw the new model for part (b) and you know the total number of cards

[Vanilla Cake]

underthesea:

Can someone help me with this maths question:


There are 2 boxes. Box and Box Y, both of which contain pens and erasers only. The respective numbers of pens and erasers in Box X are in the ratio 1:3. The respective numbers of pens and erasers in Box Y are in the ratio 5:6. The number of items in Box X is thrice the number of items in Box Y.

(a) Find the ratio of the number of pens in Box Y to the number of pens in Box X.
(b) Knowing that there are 100 more erasers in Box Y than in Box X, find the number of erasers in Box Y.

anything wrong with the question?TIA

Sorry, underthesea. This is my view as I am also waiting for Mathsguru to provide solution to my Maths problem too.Where is this question from? There is a mistake in this question stating that there are 100 more erasers in Box Y than in Box X.

I can only solve part (a) and let's wait for Mathsguru to solve part (b)

(a)
Box X
P : E
1 : 3
33 : 99

Box Y
P : E
5 : 6
20 : 24

Ratio: Total for Box X is 33+99=132 and Total for Box Y is 20+24=44
132÷44=3
fits the statement-\"The number of items in Box X is thrice the number of items in Box Y\".

Ratio of the number of pens in Box Y to the number of pens in Box X is 20:33

(b)
From workings in part (a), the number of erasers in Box X is more than the number of erasers in Box Y. This contradicts the statement given in part (b) of the question ie \"Knowing that there are 100 more erasers in Box Y than in Box X.....\"

Pls wait for Mathsguru to provide her solutions.

[CoffeeCat]

underthesea:

Can someone help me with this maths question:


There are 2 boxes. Box and Box Y, both of which contain pens and erasers only. The respective numbers of pens and erasers in Box X are in the ratio 1:3. The respective numbers of pens and erasers in Box Y are in the ratio 5:6. The number of items in Box X is thrice the number of items in Box Y.

(a) Find the ratio of the number of pens in Box Y to the number of pens in Box X.

(b) Knowing that there are 100 more erasers in Box Y than in Box X, find the number of erasers in Box Y.

anything wrong with the question?

TIA

yea i think sth's wrong too

[Vanilla Cake]

YLH88:

Hi Mathsguru,

Need your help with the below questions :

1) Doran had 8/11 of the number of game cards Thomas had. After Thomas lost 18 cards to Doran, they both had the same number of cards.

a) How many more game cards did Thomas have than Doran at first ?
b) As the game continued, Doran won more cards from Thomas. How many more cards did Thomas lose to Doran such that Doran has 3 times as many cards as him ?

I'm able to get the answer for (a), which is 36. But can't find for (b)
Thank you!

Hi YLH88,
While waiting for Mathsguru's model solution, pls see whether mine using ratio is of any use or not?

(a)
D : T
8 : 11
16 : 22

D : T
19 : 19

(16+22)÷2=19

3u=18
u=6
6u=36

At first, Thomas had 36 more game cards than Doran.

(b)
D : T
19:19
38: 38

D : T
3 : 1
57:19

6u=18 [from part (a) ie 6u=36, reduce half of 36 = 18 since 19:19 has been doubled to 38:38 in part (b)]
u=3
19u = 57
Thomas lost 57 more cards to Doran.

[YLH88]

[quote]Hi YLH88,

While waiting for Mathsguru's model solution, pls see whether mine using ratio is of any use or not?

(a)
D : T
8 : 11
16 : 22

D : T
19 : 19

(16+22)÷2=19

3u=18
u=6
6u=36

At first, Thomas had 36 more game cards than Doran.

(b)
D : T
19:19
38: 38

D : T
3 : 1
57:19

6u=18 [from part (a) ie 6u=36, reduce half of 36 = 18 since 19:19 has been doubled to 38:38 in part (b)]
u=3
19u = 57
Thomas lost 57 more cards to Doran.[/quote]Hi Vanilla Cake,

For (a), I got the answer using the model method. For the unit method, why did you change 8:11 to 16:22 ? Why do we multiple by 2 and not 3 or 4 etc ?

For (b), why do you change from 19:19 to 38:38 and 3:1 to 57:19 ?

Thank you!

[CoffeeCat]

YLH88:

[quote]Hi YLH88,

While waiting for Mathsguru's model solution, pls see whether mine using ratio is of any use or not?

(a)
D : T
8 : 11
16 : 22

D : T
19 : 19

(16+22)÷2=19

3u=18
u=6
6u=36

At first, Thomas had 36 more game cards than Doran.

(b)
D : T
19:19
38: 38

D : T
3 : 1
57:19

6u=18 [from part (a) ie 6u=36, reduce half of 36 = 18 since 19:19 has been doubled to 38:38 in part (b)]
u=3
19u = 57
Thomas lost 57 more cards to Doran.

Hi Vanilla Cake,

For (a), I got the answer using the model method. For the unit method, why did you change 8:11 to 16:22 ? Why do we multiple by 2 and not 3 or 4 etc ?

For (b), why do you change from 19:19 to 38:38 and 3:1 to 57:19 ?

Thank you![/quote]Imagine ur drawing a model.
8+11=19 is odd. do you want to draw 9 and a half units or just 38 units?

[Dharma]

YLH88:

[quote]Hi YLH88,

While waiting for Mathsguru's model solution, pls see whether mine using ratio is of any use or not?

(a)
D : T
8 : 11
16 : 22

D : T
19 : 19

(16+22)÷2=19

3u=18
u=6
6u=36

At first, Thomas had 36 more game cards than Doran.

(b)
D : T
19:19
38: 38

D : T
3 : 1
57:19

6u=18 [from part (a) ie 6u=36, reduce half of 36 = 18 since 19:19 has been doubled to 38:38 in part (b)]
u=3
19u = 57
Thomas lost 57 more cards to Doran.

Hi Vanilla Cake,

For (a), I got the answer using the model method. For the unit method, why did you change 8:11 to 16:22 ? Why do we multiple by 2 and not 3 or 4 etc ?

For (b), why do you change from 19:19 to 38:38 and 3:1 to 57:19 ?

Thank you\tDoran : 8u + 18 = 11u – 18
3u = 36 (Additional no. of cards Thomas had at first)

(b)\tDoran had = 8u = 8 x 12 = 96
Thomas had = 11u = 11 x 12 = 132

96 + 1p = 3(132 – 1p)
4p = 300
1p = 75
Additional cards Thomas lost = 75 – 18 = 57

[Emelyn]

I have one question :


Mr Tay bought a massage chair for $888. He sold it to Mr Yeo for $850. He later bought the massage chair back from Mr Yeo for $900 and sold it to Mrs Tan for $1000. How much did Mr Tayy gain ?


MTIA !