Q&A - PSLE Math

[waterfall]

pls help

I have some red and blue counters in a box, I add in 20 red counters, the ratio of my red counters to my blue counters becomes 2:3. Then I add in another 60 blue counters, the ratio of my red counters to my blue counters becomes 1:3, How may counters do I have in the box at first?

Tks

[alfretztay]

pls help

I have some red and blue counters in a box, I add in 20 red counters, the ratio of my red counters to my blue counters becomes 2:3. Then I add in another 60 blue counters, the ratio of my red counters to my blue counters becomes 1:3, How may counters do I have in the box at first?

Tks

Let the number of red and blue counters be r and b respectively.

Red : Blue
r + 20 : b
2 : 3
r + 20 : b + 60
1 : 3
3(r + 20) = 2b
3(r + 20) = b + 60
2b = b + 60
b = 60
3r + 60 = 120
r = 20
60 + 20 = 80

Ans : 80 counters.

[Daddy]

Hi all,

Please help me to explain these 2 sentences meant.

1. A watch cost $230 at store M and 15% less in store Y. Find the original price of the watch in store L.

2. Store X sells a bag at $600 which is 25% less than the price of the same bag in store Y . Find the bag in store Y.

Thank..all

[speedmaths.com]

Hi all,

Please help me to explain these 2 sentences meant.

1. A watch cost $230 at store M and 15% less in store Y. Find the original price of the watch in store L.

2. Store X sells a bag at $600 which is 25% less than the price of the same bag in store Y . Find the bag in store Y.

Thank..all

Hi,

Likely mean that some words are missing.

Cheers.

SpeedMaths
.

[speedmaths.com]

Hi all,

Please help me to explain these 2 sentences meant.

1. A watch cost $230 at store M and 15% less in store Y. Find the original price of the watch in store L.

2. Store X sells a bag at $600 which is 25% less than the price of the same bag in store Y . Find the bag in store Y.

Thank..all

Hi,

Likely mean that some words are missing.

Cheers.

SpeedMaths
.

Q2.

"Find the price of the bag in store Y."


Cheers.


SpeedMaths
.

[Daddy]

Sorry.
typo error
Q1. Find store Y instead of store L.
Q2. Find the price of the bag in store Y .

sorry...Thank .

[waterfall]

pls help

I have some red and blue counters in a box, I add in 20 red counters, the ratio of my red counters to my blue counters becomes 2:3. Then I add in another 60 blue counters, the ratio of my red counters to my blue counters becomes 1:3, How may counters do I have in the box at first?

Tks

Let the number of red and blue counters be r and b respectively.

Red : Blue
r + 20 : b
2 : 3
r + 20 : b + 60
1 : 3
3(r + 20) = 2b
3(r + 20) = b + 60
2b = b + 60
b = 60
3r + 60 = 120
r = 20
60 + 20 = 80

Ans : 80 counters.

tks

[Ender]

pls help

I have some red and blue counters in a box, I add in 20 red counters, the ratio of my red counters to my blue counters becomes 2:3. Then I add in another 60 blue counters, the ratio of my red counters to my blue counters becomes 1:3, How may counters do I have in the box at first?

Tks

Let me try using another way.

R20 : B ->2u:3u

R20:B60 -> 1:3

We can get common unit via making R20 the same.
R20:B60 -> 2u:6u

Difference between B and B60 -> 6u-3u = 60
u=20

total of R20:B-> 5u-> 100.

In the beginning is 100-20 = 80 counters.

[waterfall]

pls help

I have some red and blue counters in a box, I add in 20 red counters, the ratio of my red counters to my blue counters becomes 2:3. Then I add in another 60 blue counters, the ratio of my red counters to my blue counters becomes 1:3, How may counters do I have in the box at first?

Tks

Let me try using another way.

R20 : B ->2u:3u

R20:B60 -> 1:3

We can get common unit via making R20 the same.
R20:B60 -> 2u:6u

Difference between B and B60 -> 6u-3u = 60
u=20

total of R20:B-> 5u-> 100.

In the beginning is 100-20 = 80 counters.

thanks!

[Daddy]

Dear all. I have 2 questions to ask.




Thank you...