Q&A - PSLE Math

[Michaelia0816]

How to solve such question?

one apple cost $0.65 and one pear cost $0.75. Mrs Lee paid $28 for an equal number of apples and pears. How many fruits did she buy altogether?

( Source: Henry Park P6 Math)

How to get the answer 40? Pls help, Tianzhu?

[niza6666.028774hotmail.028774com]

Hi, I need help on this question. Thanks for helping.

Azman spent 9/14 of his money on 25 books and 8 pencils. The cost of a pencil is 1/4 that of a book. With the remainder of the money, he bought another 12 pencils and some books. How many books did he buy altogether?

[Michaelia0816]

Sorry, I already used GC to solve the question, ops… Wrong question!

[Michaelia0816]

mn:

Hi, I need help on this question. Thanks for helping.

Azman spent 9/14 of his money on 25 books and 8 pencils. The cost of a pencil is 1/4 that of a book. With the remainder of the money, he bought another 12 pencils and some books. How many books did he buy altogether?

Hi Mn,
I seemed to know how to answer this question!
- Since a pencil is 1/4 of a book, you can take a pencil as 1u, and a book as 4u.

25 books----25*4u=100u
8 pencils----8*1u=8u

9/14 of his money----100u+8u=108u
5/14 of his money----60u

The question said that he bought 12 pencils, so there is 12u.

Units spent on books-----60u-12u=48u
1 book is 4u
12 books is 48u.

25+12=37

He bought 37 books altogether.

[Michaelia0816]

[quote]Tianzhu, pls help!


From Henry Park Primary, Math, Booklet B, Q29,

A glass bottle filled with 6 identical ball-bearings weighs 1.05 kg. 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?[/quote]Can somebody help? :?

[niza6666.028774hotmail.028774com]

Hi, can someone help me with this. TIA

Mary put some red beads and blue beads in 2 jars. In Jar A, the ratio of the number of red beads to blue beads was 3:4. In Jar B, the number of red beads was twice the number of blue beads. Mary transferred half of the blue beads from Jar A to Jar B. The total number of beads in Jar A became 105 and the ratio of the number of red beads to the number of blue beads in Jar B became 5:6. What was the number of beads in Jar B after the transfer?

[MathIzzzFun]

mn:

Hi, can someone help me with this. TIA

Mary put some red beads and blue beads in 2 jars. In Jar A, the ratio of the number of red beads to blue beads was 3:4. In Jar B, the number of red beads was twice the number of blue beads. Mary transferred half of the blue beads from Jar A to Jar B. The total number of beads in Jar A became 105 and the ratio of the number of red beads to the number of blue beads in Jar B became 5:6. What was the number of beads in Jar B after the transfer?

Hi

At first, in Jar A:
Red: blue --> 3u : 4u
half of blue was transferred to Jar B --> 2u transferred,
Left in Jar A, Red: Blue --> 3u : 2u -- total 5u --> 105
1u --> 21
Number of blue transferred to Jar B = 2 x 21 = 42

At first, in Jar B,
Red: Blue = 2 : 1 --> 10p : 5p
In the end, Red : Blue = 5 : 6 --> 10p:12p -- total 22p

So, 7p --> 42, 1p--> 6

Total number of beads in Jar B after transfer --> 6 x 22 = 132

cheers.

[cimman]

Michaelia0816:

How to solve such question?

one apple cost $0.65 and one pear cost $0.75. Mrs Lee paid $28 for an equal number of apples and pears. How many fruits did she buy altogether?

( Source: Henry Park P6 Math)

How to get the answer 40? Pls help, Tianzhu?

if you are open to using algebra, here is a method:
just fill up the table, and you'll get your equation:

http://i49.tinypic.com/1z56ceu.png\">

[Michaelia0816]

thx cinman!

[Michaelia0816]

Michaelia0816:

[quote]Tianzhu, pls help!


From Henry Park Primary, Math, Booklet B, Q29,

A glass bottle filled with 6 identical ball-bearings weighs 1.05 kg. 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?

[/quote]Can somebody help?