Q&A - PSLE Math

[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?

[MathIzzzFun]

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?

Hi

add all and you will get 3 sets of (A+B+C+D) = 226.5 kg
A+B+C+D = 75.5 kg .. you can work out the rest from here..

cheers.

[MathAche]

Can anybody recommend a good book about ratios?


Having trouble with this problem because 2 variables change.

INN Store imported Notie mobile phones and Dricsin mobile phones in the ratio 8:5. After selling 120 Notie mobile phones and 135 Dricsin mobile phones, the ratio of Notie mobile phones and Dricsin mobile phones left was 8:3. How many Notie mobile phones did the store import?

[MathIzzzFun]

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?

Hi

1 pack of terrapins --> $(96+30)/2 = $63
3 packs of guppies --> $( 63-30) = $33
1 pack of guppies --> $11

$63-$11 = $52 --> 1 pack of terrapins cost $52 more than 1 pack of guppies
$52/$10.40 = 5 --> 5 terrapins/guppies in each pack.

a) number of terrapins --> 5
b) cost of 1 guppy --> $ 11/5 = $ 2.20

cheers.