Q&A - P5 Math

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Before 2 : 3
+50 +30
After 5 : 6
Note that tulip ratio has double so to simplify to 1 variable we substitute as follows
Before 4 units : 6 units
Change +50 +30
After 5 units + 25 : 6 units + 30
It is observed that 4 units + 50 = 5 units + 25 therefore 1 units = 25
Flowers at first 10 units = 250

[happyheart]

tianzhu:

happyheart:

Hi, can someone help with this question please?


Jason and Muthu had some cards. During a game, Jason lost 1/4 of his cards to Muthu in the first round. In the second round, Muthu lost 1/3 of his cards to Jason. In the third round, Jason lost 1/6 of his cards to Muthu. At the end of the three rounds, Jason had 420 cards and Muthu had 744 cards left respectively. How many cards did Jason have at first?

Thank you.

Hi

In working out this question, one key point to take note is that the number of cards stays the same throughout.

Work backwards.

5 units (5/6) ------ 420

1 unit ------ 84

6 units (6/6) ------- 504

You may continue with the rest of the calculations.




Hope this helps.

Best wishes

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Thank you Tianzhu for answering this question. Sorry, I am trying to understand but just cannot get it. In the 2nd round, how do we establish the number of cards Muthu has? Could you explain further?

[tianzhu]

happyheart:

Thank you Tianzhu for answering this question. Sorry, I am trying to understand but just cannot get it. In the 2nd round, how do we establish the number of cards Muthu has? Could you explain further?

Hi

For the second transfer
2 units (2/3) -------- 660
3 units (3/3) -------- 990

Next, the first transfer
3 units (3/4) -------- 174
4 units (4/4) -------- 232

Best wishes

[YumYum]

Hi, I need help with these qns.


1. Alice n Barry went shopping with a total of $475. After buying some items each, the amount Alice has left is 4 times the amount she spent and the amount Barry has left is thrice the amount he spent. Given that the couple has a total of $370 left, how much did each of them at first?

2. In the first week of a fund raising campaign, Class 6A raised 4 times as much money as Class 6B. In the second week, class 6A raised another $180 while class 6B raised another $120. Given that class 6A managed to raise thrice as much money as class 6B within 2 weeks, what was the total amount raised by the 2 classes in the first week?

Thanks

[YumYum]

Hi, one more qn:


Mary attempted all the 60 questions in a quiz and scored 195 marks. Given that 5 marks were awarded for each correct answer but 2 marks were deducted for each wrong answer, how many qns did Mary answer correctly?

Thanks

[tianzhu]

YumYum:

Hi, I need help with these qns.


1. Alice n Barry went shopping with a total of $475. After buying some items each, the amount Alice has left is 4 times the amount she spent and the amount Barry has left is thrice the amount he spent. Given that the couple has a total of $370 left, how much did each of them at first?

Thanks

Hi

Alice
Spent ------ 1u
Left ------- 4u

Barry
Spent ------ 1p
Left ------- 3p

4u + 3p ------- 370

1u + 1p ------- 105 (475 – 370)

3u + 3p ------- 315

1u ------- 370 – 315 --------55

1p ------- 105 – 55 ------- 50

Alice ------- 5*55 -------- 275

Barry ------- 4*50 -------- 200

Best wishes

[tianzhu]

YumYum:

2. In the first week of a fund raising campaign, Class 6A raised 4 times as much money as Class 6B. In the second week, class 6A raised another $180 while class 6B raised another $120. Given that class 6A managed to raise thrice as much money as class 6B within 2 weeks, what was the total amount raised by the 2 classes in the first week?

Hi

You may use “Units and Parts” or use MD.

At first
Class A : Class B ------- 4 units : 1 unit

Change
Class A : Class B ------- 180 : 120

In the end
Class A: Class B ------- 3 parts: 1 part

4 units + 180 ------- 3 parts

1 unit + 120 ------- 1 part
(x3)
3 units + 360 -------- 3 parts

4 units + 180 -------- 3 units + 360

1 unit ------- 180

Total amount@first week -------- 5*180 ------- 900

If you use MD, you'll see 3(1unit + 120) ------- 4 units + 180.This'll also gives 1 unit ------ 180.

Best wishes

[tianzhu]

YumYum:

Hi, one more qn:


Mary attempted all the 60 questions in a quiz and scored 195 marks. Given that 5 marks were awarded for each correct answer but 2 marks were deducted for each wrong answer, how many qns did Mary answer correctly?

Thanks

Hi

For every wrong answer, Mary lost (5+2) or 7 marks.

If all 60 answers were correct, Mary gained 300 (60*5) marks.

300 – 195 ------- 105

105/7 ------- 15

60 – 15 ------- 45

Mary answered 45 questions correctly.

Best wishes

[YumYum]

Tianzhu, thanks.

[tianzhu]

YumYum:

Tianzhu, thanks.

Hi

You're welcome.

Best wishes