Q&A - PSLE Math

[tianzhu]

Hi rossypolly


Good Afternoon

I wish to check the answers.

Are 6 big boxes and 3 small boxes correct?

Best wishes

[Apphia]

1) James spent 3/8 of his salary on food and saved 2/5 of the remainder. Then he used the rest of his salary to buy christmas presents for his friends.


a) If each present cost 1/16 of his salary, how many presents did he buy?

b) If each present cost $58, how much did james save?


2)The total length of 12 ropes and 3 ribbons is 0.252m shorter than the total length of 3 ropes and 12 ribbons.

a) what is the difference in length between one piece of rope and one piece of ribbon? (leave your answer in cm)

b) If the length of each piece of rope is 0.53m, what is the length of each piece of ribbon? ( leave your answer in cm)

Thank you !

[tianzhu]

Apphia:

1) James spent 3/8 of his salary on food and saved 2/5 of the remainder. Then he used the rest of his salary to buy christmas presents for his friends.


a) If each present cost 1/16 of his salary, how many presents did he buy?

b) If each present cost $58, how much did james save?

Hi Apphia

Good Afternoon.

Draw a bar with 16 units.

James -------- 6 units (3/8 on food)
10 units ------- remainder
4units -------savings (2/5 of the remainder)
6 units ------ Christmas presents

Each present -------- 1 unit
Number of presents ---------- 6/1 --------6

Savings --------4*58 --------- 232

Best wishes

[atutor2001]

rossypolly:

I'm stuck with this question. Hope someone can help me out with this one.


Justin baked some pies. 1/3 of the pies were chicken pies & the rest were vegetable pies. He packed 3/4 of the vegetable pies into big boxes & the rest of the vegetable pies into small boxes. each big box of vegetable pies made up 1/12 of the total no. of pies. Each small box of vegetable pies made up 1/16 of the total no of pies.

How many big boxes of vegetable pies were there?

How many small boxes of vegetable pies were there?

Let me try :

Least Common Multiple of 12 & 16 is 48

Let the total number of pies be 48 units
2/3 were vegetable pies = 2/3 x 48 units = 32 units
3/4 of veg pies in big boxes, so no. of pies in big boxes = 32 x 3/4 = 24 units
1/4 of veg pies in small boxes, so no. of pies in small boxes = 32 x 1/4 = 8 units

1 big box contains 1/12 of the total no. of pies, so no. of pies in 1 big box = 48 x 1/12 = 4 units per big box
1 small box contains 1/16 of the total no. of pies, so no. of pies in 1 small box = 48 x 1/16 = 3 units per small box

No. of big box = (Total pies in big box)/(No. of pies in 1 big box)
No. of big box = 24 units / 4 units = 6 big boxes

No. of small box = (Total pies in small box)/(No. of pies in 1 small box)
No. of small box = 8 units / 3 units = 2 and 2/3 small boxes (Where did I go wrong????)

[tianzhu]

Apphia:

2)The total length of 12 ropes and 3 ribbons is 0.252m shorter than the total length of 3 ropes and 12 ribbons.

a) what is the difference in length between one piece of rope and one piece of ribbon? (leave your answer in cm)

b) If the length of each piece of rope is 0.53m, what is the length of each piece of ribbon? ( leave your answer in cm)

Hi

You may use visual representation or letters of the alphabet to represent the solution.

1 m = 100 cm

12 ropes + 3 ribbons
3 ropes + 12 ribbons

9 ropes --------25.2 cm shorter than 9 ribbons

a)Difference in length --------25.2/9 ------2.8

b)Length of ribbon ------- 53+2.8 -------55.8

Best wishes

[Apphia]

Hi TianZhu,


Thank you for replying so quickly.

Ever so grateful !

[Yu Xuan]

Apphia:

2)The total length of 12 ropes and 3 ribbons is 0.252m shorter than the total length of 3 ropes and 12 ribbons.

a) what is the difference in length between one piece of rope and one piece of ribbon? (leave your answer in cm)

b) If the length of each piece of rope is 0.53m, what is the length of each piece of ribbon? ( leave your answer in cm)

Hi
a]
3 Rope + 12 Ribbon --> 1 unit + 0.252m
12 Rope + 3 Ribbon --> 1 unit

Comparing both statements;
9 Ribbon - 9 Robe --> 0.252m
1 Ribbon - 1 Rope --> 0.028m = 2.8cm

b]
12 Rope + 3 Ribbon + 0.252m = 3 Rope + 12 Ribbon
6.36m + 3 Ribbon + 0.252m = 1.59 m + 12 Ribbon
6.612m + 3 Ribbon = 1.59m + 12 Ribbon
9 Ribbon --> 5.3022m
1 Ribbon --> 0.558m = 55.8cm

Are those the answers?

[Apphia]

1) Mr Lee had 36 more guppies than goldfish. He sold 1/4 of the guppies and 1/5 of the goldfish. He found that he had sold 28 more guppies than goldfish. The guppies were sold $0.55 each and the goldfish at $0.85 each. What was the total amount he received?



2)Julian had 300 more cards than Faizal. Julian gave 3/5 of his cards to Faizal. Faizal then gave 1/4 of the total number of what he had then to Julian. In the end, Faizal had 300 more cards than Julian. How mny cards did Julian have at first?

How many ways can I use to solve this 2 problem sums?

Warm Rgds, Apphia

[Apphia]

Hi Yu Xuan,


The answer given is a) 0.028cm b) 0.558cm

I think the person who did the answers forgot to convert to cm. :oops:

[tianzhu]

Apphia:

2)Julian had 300 more cards than Faizal. Julian gave 3/5 of his cards to Faizal. Faizal then gave 1/4 of the total number of what he had then to Julian. In the end, Faizal had 300 more cards than Julian. How mny cards did Julian have at first?

You may use MD or Units Method to solve this question.

At First
Julian ------- 5 units + 300
Faizal ------- 5 units

After Julian gave 3/5 of his cards to Faizal.
Julian ------ 2 units + 120
Faizal ----- 5 units + 3 units + 180 ----- 8 units + 180

After Faizal than gave 1/4 of the total number of what he had then to Julian.
Julian ------- 2 units + 120 + 2 units + 45 ------- 4 units + 165
Faizal ------- 6 units + 135

In the end, Faizal had 300 more cards than Julian.
4 units + 165 + 300 ------ 6 units + 135
2units ------- 330
1 unit ------- 165

At First
Julian ------ 5 units + 300 ------ (5*165) + 300 ------1125

Best wishes