Q&A - PSLE Math

[speedmaths.com]

A club has 180 member last year. The Nos of girl decrease by 30% And the boy increase by 40%. There were as many girl n boy now.
Was there an increase or decrease in member this year? How many more or fewer?

Hi,

From 180 to 168 is a decrease of 12, not an increase.


Cheers


speedmaths
.

[chloecube]

I m trying out now.
Ya,everydayscience. From 180 to 168 is a decrease.
The answer given is increase n 18.
but I can't work out the method.

[MathIzzzFun]

I m trying out now.
Ya,everydayscience. From 180 to 168 is a decrease.
The answer given is increase n 18.
but I can't work out the method.

A club has 180 member last year. The Nos of girl decrease by 30% And the boy increase by 40%. There were as many girl n boy now.
Was there an increase or decrease in member this year? How many more or fewer?

The answer key is incorrect... I believe the answer key is based on simply assuming the net percentage as 40%-30%=10%, which gives 10% of 180 = 18.

using equal fraction/equalizing numerators method:

number of girls this year = 7/10 of number of girls last year
number of boys this year = 7/5 of number of boys last year

since there equal number of boys and girls this year
7/10 of number of girls last year = 7/5 of number of boys last year

Last year, boys --> 5u, girls 10u, total -> 15u = 180, 1u = 12
this year, boys --> 7u, girls --> 7u, total --> 14u
so, there are 1u less members --> 12 less this year.

cheers.

[belnanna]

Can someone help please.. thanks
Alan had some apples. When he packed them into bags of 7 apples,he would have 3 apples left. When he packed them into bags of 9 apples,he would be short of 6 apples. what was the least number of apples that Alan had?

[Kangkangteo]

Can someone help please.. thanks
Alan had some apples. When he packed them into bags of 7 apples,he would have 3 apples left. When he packed them into bags of 9 apples,he would be short of 6 apples. what was the least number of apples that Alan had?

7+3=10

10. 17, 24, 31, 38, 45, 52, 59, 66

9-6=3

3, 12, 21, 30, 39, 48, 57, 66

The least number of apples Alan had was 66.

[belnanna]

Can someone help please.. thanks
Alan had some apples. When he packed them into bags of 7 apples,he would have 3 apples left. When he packed them into bags of 9 apples,he would be short of 6 apples. what was the least number of apples that Alan had?

7+3=10

10. 17, 24, 31, 38, 45, 52, 59, 66

9-6=3

3, 12, 21, 30, 39, 48, 57, 66

The least number of apples Alan had was 66.

Thanks very much.. Can it be solved with model drawing ?

[belnanna]

Zachary's monthly salary is 4/5 of Jeremy's salary.Zachary's saving is 4/15 of Jeremy's saving.
Jeremy's monthly salary is 1 3/4 Zachary's monthly salary.
Find the ratio of Jeremy's expenditure to Jeremy's expenditure

Please help with this .. Been trying to find the answer for days..
thanks so much in advance

[guchengyouzi]

Thanks in advance!

I found this question.. Can anyone help please? Thanks..

Based on the ratios of the salaries and savings :

Z salary is 4/5 of J saving
4u = 4/5 * 15k
u = 3k

Z expenditure is 4u - 4k = 12k -4k = 8k
J expenditure 7u - 15k = 21k - 15k = 6k
J : Z = 6k : 8k = 3 : 4

[guchengyouzi]

Can someone help please.. thanks
Alan had some apples. When he packed them into bags of 7 apples,he would have 3 apples left. When he packed them into bags of 9 apples,he would be short of 6 apples. what was the least number of apples that Alan had?

7+3=10

10. 17, 24, 31, 38, 45, 52, 59, 66

9-6=3

3, 12, 21, 30, 39, 48, 57, 66

The least number of apples Alan had was 66.

Thanks very much.. Can it be solved with model drawing ?

Well, can be solved with algebra

If Alan packed into n bags of 7,
total no. of apples is n * 7 + 3 = 7n + 3
If packed into k bags of 9,
total no. of apples is k * 9 - 6 = 9k - 6
Therefore,
7n + 3 = 9k - 6
9k = 7n + 9
k = (7/9) n + 1
To get the smallest whole number for k, n should be 9.
n = 9
k = 8
total no. of apples is 7n + 3 = 66

[Kangkangteo]

Can someone help please.. thanks
Alan had some apples. When he packed them into bags of 7 apples,he would have 3 apples left. When he packed them into bags of 9 apples,he would be short of 6 apples. what was the least number of apples that Alan had?

7+3=10

10. 17, 24, 31, 38, 45, 52, 59, 66

9-6=3

3, 12, 21, 30, 39, 48, 57, 66

The least number of apples Alan had was 66.

Thanks very much.. Can it be solved with model drawing ?

[7][7][7][7].....[7] + 3

[9][9][9]...........[9] - 6
[7]2[7]2[7]2....[7]2 - 6

___ x 2 - 6 = 7 + 3

____ = (10 + 6)/2 = 8

9 x 8 - 6 = 66

The least number of apples Alan had was 66.