Q&A - PSLE Math

[EconsPhDTutor]

Please help. Thank you.
Sue bought some forks & spoons in the ratio of 5:2. Each spoon cost 80 cents more than a fork. She spent $172 altogether & the amount spent on the forks was $28 more than the amt spent on the spoons.
Find the cost of each spoon.

The answer is $1.80. Please see this PDF for the full worked out solution.

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www.EconsPhDTutor.com

[EconsPhDTutor]

Need help with 2 questions:

1) Amy had a total of 408 blue and yellow ribbons. She used 3/5 of her blue ribbons and bought another 32 yellow ribbons. As a result, the number of yellow ribbons she had was 1/4 the number of blue ribbons. How many more blue ribbons than yellow ones did she have at first?

2) Robbie had a total of 80 pieces of $10 notes and $50 notes. He used 1/2 of his $10 notes and withdrew another four pieces of $50 notes from the bank. After which, the number of $50 notes he had was 2/5 the number of $10 notes. Find the total value of the 80 pieces of notes he had at first.

Thanks.

The answers are

Q1. He had 392 more blue ribbons than yellow ribbons initially.
Q2. The total value of the initial 80 notes he had was 70 × $10+10 × 50 = $1,200.

Please see this PDF for the full worked out solutions.

If you found this helpful, please feel free to tell others about my services.

www.EconsPhDTutor.com

[Clueless Sotong]

Need help with 2 questions:

1) Amy had a total of 408 blue and yellow ribbons. She used 3/5 of her blue ribbons and bought another 32 yellow ribbons. As a result, the number of yellow ribbons she had was 1/4 the number of blue ribbons. How many more blue ribbons than yellow ones did she have at first?

2) Robbie had a total of 80 pieces of $10 notes and $50 notes. He used 1/2 of his $10 notes and withdrew another four pieces of $50 notes from the bank. After which, the number of $50 notes he had was 2/5 the number of $10 notes. Find the total value of the 80 pieces of notes he had at first.

Thanks.

The answers are

Q1. He had 392 more blue ribbons than yellow ribbons initially.
Q2. The total value of the initial 80 notes he had was 70 × $10+10 × 50 = $1,200.

Please see this PDF for the full worked out solutions.

If you found this helpful, please feel free to tell others about my services.

www.EconsPhDTutor.com

Hi EconsPhDTutor,

Thank you very much for your quick and timely rescue. Your explanation is very clear. Appreciate it.

Thank you.

[peggy]

Please assist.

A piggy bank contained 48 more 50 cent coins than 20 cent coins.
The total value of 50 cent coins was $72 more than the total value of 20 cent coins. How many
20-cent coins were in the piggy bank ?

Thank you.

[Sun_2010]

Please assist.

A piggy bank contained 48 more 50 cent coins than 20 cent coins.
The total value of 50 cent coins was $72 more than the total value of 20 cent coins. How many
20-cent coins were in the piggy bank ?

Thank you.

48 50c coins more = 48 x $0.5 = $24

Value of 50c coins more than 20c coins after taking away the extra 50c coins
$72 - $24 = $48

Value diff of coin : 50c-20c=30c = $0.3

No of 20c coins = $48/$0.3 = 160

[peggy]

Hi Sun_2010,

Thanks so much !

Peggy

[whywhy]

Thanks Econphd. My girl cant comprehen your solution. May I know if there are other methods to solve this question?
Sue bought some forks & spoons in the ratio of 5:2. Each spoon cost 80 cents more than a fork. She spent $172 altogether & the amount spent on the forks was $28 more than the amt spent on the spoons.
Find the cost of each spoon.

[bbc]

Thanks Econphd. My girl cant comprehen your solution. May I know if there are other methods to solve this question?
Sue bought some forks & spoons in the ratio of 5:2. Each spoon cost 80 cents more than a fork. She spent $172 altogether & the amount spent on the forks was $28 more than the amt spent on the spoons.
Find the cost of each spoon.

A similar question appeared in 2013 Ai Tong's CA1 paper.
Qn 18: On Teacher's Day, a florist sold thrice as many roses as orchids and collected $703 in total. She collected $437 more for the roses than the orchids. Given that a stalk of rose cost $1.50 more than a stalk of orchid, find the cost of a stalk of orchid.

Are the above type of questions in the PSLE syllabus?

[alfretztay]

Please help. Thank you.
Sue bought some forks & spoons in the ratio of 5:2. Each spoon cost 80 cents more than a fork. She spent $172 altogether & the amount spent on the forks was $28 more than the amt spent on the spoons.
Find the cost of each spoon.

I would solve the above as follows :
For forks :
number of forks ——- 5u
amount spent on forks ——- 5up
For spoon :
number of spoons ——- 2u
amount spent on spoon ——- 2u(p + 0.80)

5up + 2up + 1.6u = 7up + 1.6u ——- 172
5up – 2up – 1.6u = 3up – 1.6u ——- 28 (the amount spent on the forks was $28 more than the amount spent on the spoons)
10up ——-200
1up ——- 20
5up ——- 100
2u(p + 0.80) = 2up + 1.6u ——– 172 – 100 = 72
40 + 1.6u ——- 72
1.6u ——- 72 – 40 = 32
1u ——- 32/1.6 = 20
2u ——- 20 x 2 = 40 (number of spoons)
72/40 = 1.80

Ans : $1.80.

[EconsPhDTutor]

Thanks Econphd. My girl cant comprehen your solution. May I know if there are other methods to solve this question?
Sue bought some forks & spoons in the ratio of 5:2. Each spoon cost 80 cents more than a fork. She spent $172 altogether & the amount spent on the forks was $28 more than the amt spent on the spoons.
Find the cost of each spoon.

I'm sorry; I have now greatly simplified my solution. Please take a look at my solution again at the same link as before.

I hope this new solution is more helpful.