Q&A - PSLE Math

[peggy]

Hi Tianzhu,


Got it !! Very well illustrated and many thanks for sharing.


Kind regards,
Peggy

[tianzhu]

peggy:

Hi Tianzhu,

Got it !! Very well illustrated and many thanks for sharing.
Kind regards,
Peggy

Hi peggy

Good Morning.

You're welcome.

Best wishes

[chrisu]

Thanks for your working BlueBells. Yes the answer given by the teacher is $14.90 and the teacher will tell my DD today how to get it.


BTW I'm not too sure how you get \"Tony would have 65% 50c coins and 35% 20c coins\". Care to explain again?

Thanks.

BlueBells:

chrisu:

Pls help;

Tony had 15% more 50c coins than 20c coins. If there were 6 more 50c coins than 20c coins, how much money did Tony have?

Note : This question is from My Pals are here, Maths Test 6 pg.70 Q40. My DD is $31 but teacher said wrong. No answer given yet.

15% => 6 more 50c coins, so if total number of coins =100%

Then, Tony would have 65% 50c coins and 35% 20c coins

[chrisu]

Will know by today and will revert back here once I get the working from teacher. I'm anxious to know too.

tianzhu:

chrisu:

Just as I expected, the answer is $14.90 given by the teacher. The teacher will explain tomorrow.

Hi

Interesting, please share the teacher’s solution after you receive it.

If the question is worded exactly like what it’s described, the answer is $31.

Best wishes

[jieheng]

chrisu:

Pls help;


Tony had 15% more 50c coins than 20c coins. If there were 6 more 50c coins than 20c coins, how much money did Tony have?

Note : This question is from My Pals are here, Maths Test 6 pg.70 Q40. My DD is $31 but teacher said wrong. No answer given yet.

Tony had 20c and 50c coins . The percentage of these 2 types of coins added up is 100 % .

Tony had 15% more 50c coins than 20c coins ,

50c [----42.5%----][--15%--] (total 57.5%)

20c [----42.5%----]

15% -----> 6

2.5% -----> 1

number of 50c coins = 57.5% -----> 57.5%/2.5% = 23

number of 50c coins = 42.5% -----> 42.5%/2.5% = 17

the amount of money that Tony had = 23 * $0.50 + 17*$0.20 = $11.50 + $3.40 = $14.90 (Ans)

[chrisu]

Thank you for the detailed illustration, Jieheng.


But I still wonder how \"Tony had 15% more 50c coins than 20c coins.\" can be interpreted as \"The percentage of these 2 types of coins added up is 100 % .\"

I've come across a similar question in http://thesingaporemaths.com/p6math3f.swf and it does not show that both add up to be 100%. I believe such question is always the usual testing of English than Maths.... :x

jieheng:

chrisu:

Pls help;

Tony had 15% more 50c coins than 20c coins. If there were 6 more 50c coins than 20c coins, how much money did Tony have?

Note : This question is from My Pals are here, Maths Test 6 pg.70 Q40. My DD is $31 but teacher said wrong. No answer given yet.

Tony had 20c and 50c coins . The percentage of these 2 types of coins added up is 100 % .

Tony had 15% more 50c coins than 20c coins ,

50c [----42.5%----][--15%--] (total 57.5%)

20c [----42.5%----]

15% -----> 6

2.5% -----> 1

number of 50c coins = 57.5% -----> 57.5%/2.5% = 23

number of 50c coins = 42.5% -----> 42.5%/2.5% = 17

the amount of money that Tony had = 23 * $0.50 + 17*$0.20 = $11.50 + $3.40 = $14.90 (Ans)

[Suz855]

Tony had 15% more 50c coins than 20c coins. If there were 6 more 50c coins than 20c coins, how much money did Tony have?


Note : for percentage, generally, the object or individual after the word 'than' will be the base (100%)

Thus in this question
100%\t20c
115%\t50c

15%  6
5% -> 2
100%\t2x20 = 40 (20c)
115%\t46 (50c)
46 x 0.5 =23
40 x 0.2 = 8
Amt $31

Hope this help,

[BlueBells]

Suz855:

Tony had 15% more 50c coins than 20c coins. If there were 6 more 50c coins than 20c coins, how much money did Tony have?


Note : for percentage, generally, the object or individual after the word 'than' will be the base (100%)

Hmmmmm ... my interpretation of the question is:

Tony has X amount with him / in his pocket or wallet in a combination of 50c and 20c coins. He has 15% more 50c coins than 20c coins; therefore, I would use X amount as my base, which is 100%; which will then equate to 65% of 50c coins and 35% of 20c coins, resulting in X amount being S$14.90.

[tianzhu]

chrisu:

Will know by today and will revert back here once I get the working from teacher. I'm anxious to know too.

Hi

First, let’s see the teacher explanation first.

We cannot read the intention of the question setter, what we can rely on is our understanding on the concepts of percentages.

Tony had 15% more 50c coins than 20c coins. If there were 6 more 50c coins than 20c coins, how much money did Tony have?

Based on the question, we are given the understanding that the number of 50 cents coins is 15% more than the number of 20 cents coins.

Next compare your question with this common question in P6 percentage.

Jian Zhong has $50.Ming Ming has 20% more money than Jian Zhong.How much money does Ming Ming have?

How would one interpret the second question?

Best wishes

[shurley197323]

Pls help. John had some sweets. If he gives 12 sweets to each friend,he will have 10 sweets left. If he gives 18 sweets to each friend, shee needs 140 more sweets.

(This is a common question but this time is 140 more
normally is how many sweets lefts)