Q&A - PSLE Math

[Pen88n]

You may want to ask your question in the Maths thread rather than starting a new topic on just 1 maths question.


Mod, merge this to P5/6 Maths thread? Thanks

[Dreamerz]

hi i need help for these 2 questions:


1) mr tan had a total of 960 fruits. 30% of the fruits in basket A were oranges and the rest were pears. 40% of the fruits in basket B were pears and the rest were oranges. after some fruits were transferred from A to B and B to A, 25% of the fruits in basket A and 75% of the fruits in basket B were oranges. how many fruits are there in basket A in the end?

2)the total of boys and girls in classes A and B was 100% more than the total number of boys in the 2 classes. the ratio of the number of boys to the number of girls in class A was 2:3. the ratio of the number of boys to the number of girls in class B was 1:4. if there are 18 more boys in class A than B, how many pupils are there in Class A altogether?

TIA

[Pen88n]

6*(1+2+3+…+39+40) = 6*(41*20) = 4920

[Michaelia0816]

Dear Dreamerz,

Let recall,
Basket A got 30% of oranges, 70% of pears
Basket B got 40% of pears, 60% of oranges
Count the % of oranges and pears then divide!
If u don understand, tell me

[Michaelia0816]

Strange question of question2!!! Don quite understand

[atutor2001]

Dreamerz:

hi i need help for these 2 questions:


2)the total of boys and girls in classes A and B was 100% more than the total number of boys in the 2 classes. the ratio of the number of boys to the number of girls in class A was 2:3. the ratio of the number of boys to the number of girls in class B was 1:4. if there are 18 more boys in class A than B, how many pupils are there in Class A altogether?

TIA

Hi Dreamerz, if the ratio of boy to girl in class B is 4:1 instead, then I know how to do. The answer is 135.

The steps are :

Let the number of boys in A be 2p and the girls in A be 3p
Let the number of boys in B be 4u and the girls in B be 1u

Total children is 100% more than total boys means that \"Total children is 200% if total boys is 100%. Therefore, total girls is also 100% i.e. total boys equal total girls.

Total boys = 2p + 4u
Total girls = 3p + 1u

They are equal, so 2p + 4u = 3p +1u --> 3u = 1p

Therefore, the number of boys in A = 2p = 6u and the girls in A = 3p = 9u

Difference in boys of the 2 classes = 6u - 4u = 2u

2u --> 18
1u --> 9
15u --> 9 x 15 = 135 (total in A)

[match3frog]

Hi, anybody has the following from MGS SA1 Paper 2:


1) Question 4 - figure is missing from my paper

In the figure below, not drawn to scale, A is the centre of the circle. The diameter of the circle is 12cm. What is the perimeter of the figure shown below?

2) Question 16 - ??? missing from this question below

In an amusement park, there were 3/8 as many girls as boys. After 20 boys left that park and 12 girls entered the park, the ratio of boys to girls became ???
(a) How many girls were at the amusement park at first? (ans: 144)
(b) How many children were at the amusement park at the end? (ans: 520)

Thanks!

[jarenchuatw]

How many 6cmx4cm rectangles can be cut from the 173cm by 166cm rectangle?


I used the following method to get the answer, but was told it was wrong

(173x166cm) divided by (6cmx4cm) - approximately 1196 small rectangles can be cut.

The answer is 1189.

So why the above method is wrong, and if so, what is the correct method :?

[elkniwt]

Hi,


Need help on this question:
Jack was given 3 times as much allowance as Jill. Jack spent $25 a day and Jill spent $11 a day. When Jill spent all her allowance, Jack had $256 left.
a) Find the total amount of allowance Jack and Jill were given.
b) Find the number of days it took for Jill to spend all her allowance.

Regards.

[CRAZYBANANA]

I don’t seem to get the ans u stated but u have to use

173/6 = 28.83 but u can use 28
166/4 =41.5 but u can only use 41
Then is 28x41=1148
Or to maximize the 173x166,
173/4 = 43.25 but u can use only 43
166/6 =27.67 but u can use only 27
Then is 43x27=1161