Q&A - PSLE Math

[Bunny27]

tianzhu:

MathAche:

Nanyang P6 2011 CA1

Q16) Sushila went shopping. She spent $588 on 2 dresses, 3 skirts and 2 pairs of sunglasses. The total amount spent on the dresses was 0.4 of the total amount spent on the skirts and sunglasses. The total amount spent on the sunglasses was 1/3 of the total amount spent on dresses and skirts.
(a) how much did she spend on the 2 pairs of sunglasses?
(b) what was the cost of the third skirt if the average cost of the other 2 skirts was $88?

Looking for a model to help explain to my kid.

Hi

You may want to consider working in term of units instead of MD. If you prefer some form of pictorial representation, you may draw some boxes to show the units.

The total amount spent on the dresses was 0.4 of the total amount spent on the skirts and sunglasses.

Dresses:( skirts and sunglasses) ----- 4:10 ------ 2:5 (total 7 units) ------ 8:20

The total amount spent on the sunglasses was 1/3 of the total amount spent on dresses and skirts.

sunglasses:( dresses and skirts) ----- 1:3 (total 4 units) ------- 7:21

Make the total units the same.

dresses:skirts :sunglasses ------- 8:13:7

28 units ------ 588
1 unit ------ 21

(a)Amount spent on 2 pairs of sunglasses -------7*21 ------ 147

(b)(13*21) – (2*88) ------ 97

Best wishes

Hi, can someone help for this question:

A box contains 25 similar reams of photostating paper. The total mass of the box with 2/5 of papers is 36kg lighter than the box with all it's contents. The mass of the box is 3/5 times that of a ream of paper. What is the total mass of the box with all its contents?
The ans is 61.44kg but I keep getting 64kg. Can someone try for me which is correct?

Thanks

[MathIzzzFun]

Bunny27:

tianzhu:

[quote=\"MathAche\"]Nanyang P6 2011 CA1

Q16) Sushila went shopping. She spent $588 on 2 dresses, 3 skirts and 2 pairs of sunglasses. The total amount spent on the dresses was 0.4 of the total amount spent on the skirts and sunglasses. The total amount spent on the sunglasses was 1/3 of the total amount spent on dresses and skirts.
(a) how much did she spend on the 2 pairs of sunglasses?
(b) what was the cost of the third skirt if the average cost of the other 2 skirts was $88?

Looking for a model to help explain to my kid.

Hi

You may want to consider working in term of units instead of MD. If you prefer some form of pictorial representation, you may draw some boxes to show the units.

The total amount spent on the dresses was 0.4 of the total amount spent on the skirts and sunglasses.

Dresses:( skirts and sunglasses) ----- 4:10 ------ 2:5 (total 7 units) ------ 8:20

The total amount spent on the sunglasses was 1/3 of the total amount spent on dresses and skirts.

sunglasses:( dresses and skirts) ----- 1:3 (total 4 units) ------- 7:21

Make the total units the same.

dresses:skirts :sunglasses ------- 8:13:7

28 units ------ 588
1 unit ------ 21

(a)Amount spent on 2 pairs of sunglasses -------7*21 ------ 147

(b)(13*21) – (2*88) ------ 97

Best wishes

Hi, can someone help for this question:

A box contains 25 similar reams of photostating paper. The total mass of the box with 2/5 of papers is 36kg lighter than the box with all it's contents. The mass of the box is 3/5 times that of a ream of paper. What is the total mass of the box with all its contents?
The ans is 61.44kg but I keep getting 64kg. Can someone try for me which is correct?

Thanks :)[/quote]Hi

61.44 kg is correct.

3/5 of papers --> 36 kg
15 reams --> 36 kg, 1 ream --> 2.4 kg,
Box --> 0.6 x 2.4 kg = 1.44 kg
25 reams --> 60 kg
total --> 61.44 kg

cheers.

[portal]

I have this question to ask.Mr Yeo always gives 80% of his money to his wife.

However,his income for this month was 35% less than last month.
As a result, he amount of money he gave to his wife decreased by $175.
What was his income last month? :?: :?:

[portal]

I have this question to ask. My salary is 1/5 more than my sister but 20% less than my brother.

If our total salary is $11 100, what is my sisters salary?

[MathIzzzFun]

portal:

I have this question to ask.Mr Yeo always gives 80% of his money to his wife.

However,his income for this month was 35% less than last month.
As a result, he amount of money he gave to his wife decreased by $175.
What was his income last month? :?: :?:

Hi

last month's income --> 100u, wife --> 80u
this month's income --> 65u, wife --> 0.8 x 65u = 52u
80u - 52u = 28u
28u --> $ 175, 1u --> $6.25
last month's income -->100u --> $625

cheers.

[MathIzzzFun]

portal:

I have this question to ask. My salary is 1/5 more than my sister but 20% less than my brother.

If our total salary is $11 100, what is my sisters salary?

Hi

me: sister --> 120 : 100 --> 6 : 5
me: brother --> 80 : 100 --> 4 : 5
me : sister : brother --> 12u : 10u : 15u
Total 37 u --> $ 11100
sister's salary --> 10u --> 10/37 x $11100 = $3000

cheers.

[Viste]

This is a good topic on Simultaneous equations: http://www.mathsrev.com/simultaneous-equations/

[TheCoolGuy]

Just wondering… Is the Math PSLE Paper much harder than the school SA Papers, especially P6 SA1???

Thanks

[MathAche]

Help needed (Nanyang P6 CA1 2011)


Leon bought some terrapins and guppies for a total of $96. He bought 3 times as many guppies as terrapins. He paid $30 more for the terrapins than the guppies. Each terrapin cost $10.40 more than each guppy.
(a) how many terrapins did he buy?
(b) what was the cost of each guppy?

[MathAche]

Help needed (Nanyang P6 CA1 2011). Thank you.


The mass of four sacks of rice A, B, C, D were recorded. 3 sacks of rice were weighed at a time.
Sacks A,B and C weighed a total of 55 kg
Sacks B,C and D weighed a total of 56 kg
Sacks A,C and D weighed a total of 57 kg
Sacks A,B and D weighed a total of 58.5 kg

What was the total mass of Sack B and Sack D?