Q&A - PSLE Math

[tianzhu]

Winx5015:

(1). Kelly and Susan had some money each. If Kelly spent 4100 each day and Susan spent $50 each day, Kelly will still have $500 left when Susan had spent all her money. If Kelly spent $50 each day and Susan spent $100 each day, Kelly will still have $2300 left when Susan had spent all her money. How much did each of them have?

Hi

Please study the solution for a similar question.It will help to solve your question.

For your question,

3 units ------- 1800 (2300-500)

1 unit ------ 600

Kelly ------- 2900

Susan ------1200

Best wishes

http://farm6.staticflickr.com/5142/5614468685_555807d62e_z.jpg\">

[Winx5015]

Hi Nebbermind,


U are right. should be $100 instead of 4100. Sorry, is a typo erro.

Thanks.

[tianzhu]

Winx5015:

(2). Stefane and Lee Ling have some money. If Stefane gives Lee Ling $4.50, the two girls will have an equal amount of money. If Lee Ling gives $4.50 to Stefane, Stefane will have twice as much as Lee Ling. How much money do the 2 girls have altogether?

Thanks!

Hi

Please study this solution for an earlier question.

Quite similar, it may help.

For your question, the transfers are in two directions.

1 unit ----- 4.5+4.5+4.5+4.5 ----- 18

S ----- 31.5
LL ----- 22.5
Total ----- 54

Best wishes.

http://farm2.staticflickr.com/1389/5112750348_b9f86799b4_z.jpg\">

[genevieve08]

(1) 100 - 50 = 50

2300/50 = 46
46x50 = 2300
k-->2300+2300 = 4600
4600-500=4100
4100/4100 = 0
50/0 = 50

Kelly have $4600 and Susan have $50


Scenario 1 Scenario 2 (2)
S : L S:L
1u+4.50:1u-4.50 2p-4.50:1p+4.50
3u+4.50 :3-4.50 4p-4.50:2p+4.50

4.5x4 = 18
18x2 =36 [because comparing two scenarios ]
36 + 4.5 = 40.5
40.5/4 = 10.125
10.125x2 = 20.25
20.25+4.5 = 24.75
24.75 + 36 = 60.75

they have $60.75 altogether.
:siam:

[Nebbermind]

genevieve08:

(1) 100 - 50 = 50

2300/50 = 46
46x50 = 2300
k-->2300+2300 = 4600
4600-500=4100
4100/4100 = 0
50/0 = 50

Kelly have $4600 and Susan have $50


Scenario 1 Scenario 2 (2)
S : L S:L
1u+4.50:1u-4.50 2p-4.50:1p+4.50
3u+4.50 :3-4.50 4p-4.50:2p+4.50

4.5x4 = 18
18x2 =36 [because comparing two scenarios ]
36 + 4.5 = 40.5
40.5/4 = 10.125
10.125x2 = 20.25
20.25+4.5 = 24.75
24.75 + 36 = 60.75

they have $60.75 altogether.
:siam:

Q1. If Susan had $50, she would not have been able to spend $100.

Q2. I think Tianzhu provided the correct solution above

[MathIzzzFun]

Winx5015:

Hi,


Pse help me with the following questions!

(1). Kelly and Susan had some money each. If Kelly spent $100 each day and Susan spent $50 each day, Kelly will still have $500 left when Susan had spent all her money. If Kelly spent $50 each day and Susan spent $100 each day, Kelly will still have $2300 left when Susan had spent all her money. How much did each of them have?


Thanks!

Hi

If Kelly spent $50 & Susan spent $100, Kelly will have $2300 left
Kelly's spending : Susan's spending --> 1u : 2u

Kelly's money --> 1u + $2300
Susan's money --> 2u

If Kelly spent $100 & Susan spent $50, Kelly will have $500 left
Kelly's spending : Susan's spending --> 4u : 2u
Kelly's money --> 4u + $500
Susan's money --> 2u

So, 4u + $500 = 1u + $2300
3u --> $ 1800
1u --> $ 600

4u + $ 500--> $2900
2u --> $ 1200
Kelly had $ 2900, Susan had $ 1200

cheers.

[Nebbermind]

kamom:

Given that one and only one of the following statements is correct, which one is correct?


1)All the statements below are correct
2)None of the statements below is correct
3)One of the statements above is correct
4)All of the statements above is correct
5)None of the statements above is correct

Ans is (5), can someone explain to me :idea:

THANKS A MIL

The fact that ONLY one is correct rules out (1) and (4).

If (3) is TRUE, then (2) has to be TRUE since (1) is already FALSE. But that cannot be possible since (2) says that (3) is FALSE. Since either (3) or (2) being TRUE will contradict each other, we are left with (5).

[genevieve08]

Sorry my first answer is wrong.


But Kelly = $2900 and Susan = $1200 is not right either, working backwards:

First scenario Kelly spent $100 per day and left $500

Taking $2900 - $500 = $2400
2400 / 100 = 24 days

Taking scenario 2 for Kelly

2900 - 2300 = 600
600 / 50 = 12 days

[Winx5015]

Hi Nebbermind, tianzhu, MathIzzzFun & genevieve08,


Thanks all for your help!

Have a nice day

[Winx5015]

Hello,


Following are 2 questions on ratio.

(1). The ratio of Gopal's mass to Siew Leng's mass is 6:5. If Gopal loses 4Kg and Siew Leng gains 3Kg, Siew Leng will be 1Kg heavier than Gopal.
(a). Express siew Leng's mass as a fraction of the total mass.
(b). What is Gopal's actual mass?

(2). Seng Chye and Rani have different amounts of money. If Rani gives $24 to Seng Chye, the ratio of the amount of money she has to what Seng Chye has will be 4:9. If Seng Chye gives $21 to Rani, they will have the same amount of money.
(a). How much more money does Seng Chye have than Rani?
(b). How much money does Rani have?


Thanks!