Q&A - PSLE Math

[superksmum]

Pls help:


There were 1000 students at the parade ground and indoor sports hall. 40% of the 600 students at the parade ground were girls. 60% of the students at the indoor sports hall were girls. After some students in both venues moved from one venue to the other,30% of the students in the parade ground and 70% of the students at the indoor sports hall were girls. How many students were there in the indoor sports hall after the movement had taken place?

Thank you.

[Neat]

[quote]Hi! Thanks speedmaths.com for solving the problem and the introduction of advanced model method. [/quote]

[superksmum]

Sorry another 2 questions:


1) A glass bottle filled with 6 identical ball bearings weighs 1.05kg. The same bottle when filled with 8 marbles weighs 830g. The mass of each ball-bearing is five times the mass of each marble. What is the mass of the empty glass?

2) John donated 1/4 of his cards and Joseph donated 2/3 of his cards. They have the same number of cards left. What is the ratio of the number of cards John has to the number of cards Joseph has at first?

Thank you.

[2632parent]

Need help on the following question


1) An equal volume of water is poured into Tank A and B . If the base area of Tank A is 60% greater than the base area of Tank B and the difference in their water level is 6cm, find the water level in Tank A.

Many thanks in advance

[Chan09]

Is there a faster method to solve this?

Eveyday A gets 10 additional new cards. On every third day he gives 3 cards away. If A starts with 8 cards on the first day, on which day will he have exactly 180 cards?

Thank you.

[balu_priya]

My friend who is too shy to post asked me to help her to post on ksp.

Would appreciate help on the following questions:

1.Sam is 5times as old as his sister. iN 10 yrs time Sam will be 12 yrss less than thrice his sisters age then. How much older is Sam than his sister?


2. Father has given Claire and Jane each a certain amount money to spend . If Claire spends $30 each day and Jane spends$20each dayclaire would have $100 left by the time. Jane spends all her money if Claire spends $ 20each day and Jane spends $ 30 each day Claire would have $ 600 left by the time Jane spends all her money . Find the total amount of money given to Claire?

[MathIzzzFun]

balu_priya:

My friend who is too shy to post asked me to help her to post on ksp.

Would appreciate help on the following questions:



2. Father has given Claire and Jane each a certain amount money to spend . If Claire spends $30 each day and Jane spends$20each dayclaire would have $100 left by the time. Jane spends all her money if Claire spends $ 20each day and Jane spends $ 30 each day Claire would have $ 600 left by the time Jane spends all her money . Find the total amount of money given to Claire?

here are 4 approaches to solve such questions -

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http://i46.tinypic.com/ejvktd.png\">

cheers.

[MathIzzzFun]

balu_priya:

My friend who is too shy to post asked me to help her to post on ksp.

Would appreciate help on the following questions:

1.Sam is 5times as old as his sister. iN 10 yrs time Sam will be 12 yrss less than thrice his sisters age then. How much older is Sam than his sister?

Age now,
Sam's sister --> 1 unit
Sam --> 5 units

10 years' time,
Sam's sister --> 1 unit + 10 -- \"thrice\" --> 3 units + 30
Sam --> 5 units + 10

Sam is 12 years less than his sister:
5 units+ 10+12 = 3 units + 30
1 unit --> 4

4 units --> 16

Sam is 16 years older than his sister.

cheers.

[MathIzzzFun]

2632parent:

Need help on the following question


1) An equal volume of water is poured into Tank A and B . If the base area of Tank A is 60% greater than the base area of Tank B and the difference in their water level is 6cm, find the water level in Tank A.

Many thanks in advance

Volume of water in A = Volume of water in B
Base area of A : Base Area of B = water level in B : water level in A
water level in B : water level in A = 160 : 100 --> 8u : 5u

3u --> 6 cm, 1u --> 2 cm
water level in A --> 10 cm

cheers.

[superksmum]

Please help,


A large warehouse had a total of 2180 black, red and white t-shirts for sale. The ratio of the number of black t-shirts to the number of red t-shirts was 3:1. After 2/5 of the black t-shirts, 1/3 of the white t-shirts and none of the red t-shirts were sold on the first day, the were 1504 t-shirts left. How many red t-shirts did the warehouse have at first?

Thank you.