Q&A - PSLE Math
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usaik:
similar questions discussed here:Hello,
I need help on the following question. Can anyone please help. THANKS.
http://i42.tinypic.com/ap8z03.jpg\">
There were 2 identical flights of steps. For the first of steps, Bobby walked up some steps and ran 9 steps in a total of 78 seconds. For the 2nd flight of steps, Bobby walked up some steps and ran 17 steps in a total of 48 seconds. How long will bobby take to walk up both flights of steps??
-- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=27&t=6373&start=2790
There were 2 identical flights of steps.For the 1st flight of steps , Samuel walked up some steps and ran 7 steps in 67seconds. For the 2nd flight of steps, Samuel walked up some steps and ran 15 steps in 43seconds. How long will Samuel take to walk up both flight of steps?
--- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=3750
Every Saturday, John will go for his usual exercise. if he runs up 32 steps and walks up 68 steps , he will take 184 seconds. If he runs up 50 steps and walks 50 steps, he will take 175 seconds. If he runs at the same rate throughout the whole exercise, how long will he take to run the 100 steps?
-- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=9140
cheers.
-- -
starfish53:
this was discussed :Can anyone help me with the following question?
Q2) Mary bought some red marbles and gave half to Noel.
Noel bought some blue marbles and gave half to Mary.
Mary lost 16 red marbles and Noel lost 55 blue marbles.
The ratio of Mary's red marbles to blue marbles became 18 : 85 and
the ratio of Noel's red marbles to blue marbles became 7 : 20.
How many red marbles marbles did Mar buy?
Thanks in advance.
- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=9190
- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=9200
similar questions at:
- http://www.flickr.com/photos/mathizzzfun/6943541872/in/set-72157632928079102
- http://www.flickr.com/photos/mathizzzfun/8196644004/in/set-72157632037121311
cheers. -
starfish53:
Tina's money --> 4 units,Can anyone help me with the following question?
Q1) 3/5 of Bette's money is $324 more than 3/4 of Tina's money.
Bette has twice as much as Tina.
a) How much does Tina have?
b) How much does Bette have?
Thanks in advance.
3/4 of Tina's money --> 3 units
3/5 of Bette's money -->3 units + $324 = 3 x (1 unit + $108)
Bette's money (5/5) --> 5 x (1 unit + $108) = 5 units + $540
Bette has twice as much as Tina
so,
5 units + $540 = 8 units
1 unit --> $180
Tina's money --> $ 720
Bette's money --> $ 1440
cheers. -
Dear MathIzzzFun,
Thank you so much for your help!
Regards/ -
need help in the following question:
1) Tom’s present age is twice more than Sam’s age years ago. Today, Sam’s age is the same number of years ago. How old is Tom now if the sum of their present age is 30? -
ozora:
any missing info ?need help in the following question:
1) Tom's present age is twice more than Sam's age years ago. Today, Sam's age is the same number of years ago. How old is Tom now if the sum of their present age is 30?
If the sentence is \"Today, Sam's age is the same as Tom's age same number of years ago\", then
Now, Sam's age --> 12 years, Tom's age --> 18 years
6 years ago, Sam's age --> 6 years, Tom's age --> 12 years.
cheers. -
starfish53:
For this kind of question, I like to use simultaneous equations because you just need to draw the model according to the logical understanding of the facts. This is useful especially for those who are good in interpreting the facts into models.Can anyone help me with the following question?
Q1) 3/5 of Bette's money is $324 more than 3/4 of Tina's money.
Bette has twice as much as Tina.
a) How much does Tina have?
b) How much does Bette have?
Thanks in advance.
http://i42.tinypic.com/3169jeu.jpg\"> -
MathIzzzFun:
yes there is missing infor.thanks for the highlight. sam's age is tom's age the same number of years ago.
any missing info ?ozora:
need help in the following question:
1) Tom's present age is twice more than Sam's age years ago. Today, Sam's age is the same number of years ago. How old is Tom now if the sum of their present age is 30?
If the sentence is \"Today, Sam's age is the same as Tom's age same number of years ago\", then
Now, Sam's age --> 12 years, Tom's age --> 18 years
6 years ago, Sam's age --> 6 years, Tom's age --> 12 years.
cheers. -
ozora:
need help in the following question:
1) Tom's present age is twice more than Sam's age years ago. Today, Sam's age is Tom's age the same number of years ago. How old is Tom now if the sum of their present age is 30?
Using units/parts method:
Number of years ago,
Tom's age --> 1p
Sam's age --> 1u
Now,
Tom's age --> 3u
Sam's age --> 1p
Age difference remains the same, therefore,
1p-1u = 3u-1p
1p --> 2u
Now,
Tom's age --> 3u
Sam's age --> 2u
Total --> 5u --- 30
1u --> 6
Tom's age now --> 18
cheers. -
hi. Cld someone help me on this pls?
The ratio of the number of Donovan’s stickers to the number of Hong Yi’s stickers is 10:3. After Donovan gave hong Yi 1/5 of his stickers, hong Yi had 30 stickers less than Donovan. How many stickers did Donovan give to Hong yi?
thanks -
rzz:
At firsthi. Cld someone help me on this pls?
The ratio of the number of Donovan's stickers to the number of Hong Yi's stickers is 10:3. After Donovan gave hong Yi 1/5 of his stickers, hong Yi had 30 stickers less than Donovan. How many stickers did Donovan give to Hong yi?
thanks
Donovan 10u
Hong Yi 3u
1/5 of 10u = 2u
Donovan gave 2u to Hong Yi
In the end
Donovan 10u - 2u = 8u
Hong Yi 3u + 2u = 5u
Hong Yi had 30 stickers less than Donovan
8u - 5 u -> 30
3u -> 30
1u -> 10
No of stickers that Donovan gave to Hong yi was 2u -> 2*10 = 20 -
MathIzzzFun:
thanksozora:
need help in the following question:
1) Tom's present age is twice more than Sam's age years ago. Today, Sam's age is Tom's age the same number of years ago. How old is Tom now if the sum of their present age is 30?
Using units/parts method:
Number of years ago,
Tom's age --> 1p
Sam's age --> 1u
Now,
Tom's age --> 3u
Sam's age --> 1p
Age difference remains the same, therefore,
1p-1u = 3u-1p
1p --> 2u
Now,
Tom's age --> 3u
Sam's age --> 2u
Total --> 5u --- 30
1u --> 6
Tom's age now --> 18
cheers. -
Need some help in these 2 questions.
Q1. http://i42.tinypic.com/35lsxsg.jpg\">
Q2. Ali and Dee shared a box of blue and green markers equally.
Ali took 3 times as many blue markers as Dee.
The ratio of the number of green markers Dee took to The ratio of the number of green markers Ali took was 9: 5.
what was the ratio of Ali's blue markers to green markers?
the answer given for this is 6:5 but i got 3:5 -
ozora:
Since the box of markers are shared equally, each has same total number of markersNeed some help in these 2 questions.
Q1. http://i42.tinypic.com/35lsxsg.jpg\">
Q2. Ali and Dee shared a box of blue and green markers equally.
Ali took 3 times as many blue markers as Dee.
The ratio of the number of green markers Dee took to The ratio of the number of green markers Ali took was 9: 5.
what was the ratio of Ali's blue markers to green markers?
the answer given for this is 6:5 but i got 3:5
ratio of Ali's green : Dee's green = 5 : 9 -- difference of 4
ratio of Ali's blue : Dee's green = 3 : 1 = 6 : 2 -- difference of 4
(if Ali has 4 more green than Dee, than Dee must also have 4 more blue than Ali since the total is the same)
ratio of Ali's blue : green = 6 : 5
similar question here -- http://www.flickr.com/photos/mathizzzfun/5703951396/
cheers. -
ozora:
Circle, total --> 8u, shaded --> 2u, unshaded --> 6uNeed some help in these 2 questions.
Q1. http://i42.tinypic.com/35lsxsg.jpg\">
Rectangle, total --> 6p, shaded --> 2p, unshaded --> 4p
Circle + Rectangle, total --> 8u + 6p
Square, shaded --> 2u + 2p --- 40%
Square, total --> 5u + 5p
Square, total : Circle + Rectangle, total
= 5 : 7
--> 5u + 5p : 7u +7p
so, 8u + 6p = 7u + 7p
1u = 1p
Square, total --> 10u, shaded --> 4u, unshaded --> 6u
Circle, total --> 8u, shaded --> 2u, unshaded -->6u
Rectangle, total --> 6u, shaded --> 2u, unshaded --> 4u
Shaded, total : unshaded, total
--> 4u : 16u
= 1: 4
cheers. -
Please help with this question~ thanks in advance
Mrs Wong baked 235 more chocolate cakes than durian cakes. After selling 2/5 of the chocolate cakes and half of the durian cakes, she had 152 cakes left. How many cakes did she sell? -
Hi
Please help me with these questions from2012 ACS
ACS Paper 1 Qn 15
Qn 15 The table with 4 columns is filled with numbers in a certain pattern. The first 4 rows of the table are shown below.
Column A B C D
Row 1 1 3 5 Black box
Row 2 black box 11 9 7
Row 3 13 15 17 Black Box
Row 4 Black box 23 21 19
In which column will the number 135 appear?
Qn 30 Every Saturday, Mabel will go for her usual exercise. If she runs up 32 steps and walks up 68 steps, she will take 184 seconds. If she runs up 50 steps and walks 50 steps, she will take 175 seconds. If she runs at the same rate throughtout the whole exercise, how long will she take to run the 100 steps?
Thank you in advance -
Peace Charlie:
Durian cakes --> 10 units,Please help with this question~ thanks in advance
Mrs Wong baked 235 more chocolate cakes than durian cakes. After selling 2/5 of the chocolate cakes and half of the durian cakes, she had 152 cakes left. How many cakes did she sell?
1/2 of durian cakes --> 5 units
Chocolate cakes --> 10 units + 235,
Sold 2/5 of chocolate cakes --> 4 units + 94
Left 3/5 of chocolate cakes --> 6 units + 141
Total sold --> 5 units + 4 units + 94 = 9 units + 94
Total left --> 5 units + 6 units + 141 = 11 units + 141
11 units + 141 --> 152
1 unit --> 1
Total number of cakes sold --> 9 x 1 + 94 = 103
cheers. -
Easy-going:
Hi
Please help me with these questions from2012 ACS
Qn 30 Every Saturday, Mabel will go for her usual exercise. If she runs up 32 steps and walks up 68 steps, she will take 184 seconds. If she runs up 50 steps and walks 50 steps, she will take 175 seconds. If she runs at the same rate throughtout the whole exercise, how long will she take to run the 100 steps?
Thank you in advance
similar questions discussed here:
There were 2 identical flights of steps. For the first of steps, Bobby walked up some steps and ran 9 steps in a total of 78 seconds. For the 2nd flight of steps, Bobby walked up some steps and ran 17 steps in a total of 48 seconds. How long will bobby take to walk up both flights of steps??
-- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=27&t=6373&start=2790
There were 2 identical flights of steps.For the 1st flight of steps , Samuel walked up some steps and ran 7 steps in 67seconds. For the 2nd flight of steps, Samuel walked up some steps and ran 15 steps in 43seconds. How long will Samuel take to walk up both flight of steps?
--- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=3750
Every Saturday, John will go for his usual exercise. if he runs up 32 steps and walks up 68 steps , he will take 184 seconds. If he runs up 50 steps and walks 50 steps, he will take 175 seconds. If he runs at the same rate throughout the whole exercise, how long will he take to run the 100 steps?
-- http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=9140
cheers. -
Easy-going:
Hi
Please help me with these questions from2012 ACS
ACS Paper 1 Qn 15
Qn 15 The table with 4 columns is filled with numbers in a certain pattern. The first 4 rows of the table are shown below.
Column A B C D
Row 1 1 3 5 Black box
Row 2 black box 11 9 7
Row 3 13 15 17 Black Box
Row 4 Black box 23 21 19
In which column will the number 135 appear?
Thank you in advance
one possible way is to use the quotient/remainder method...
http://i42.tinypic.com/15horia.jpg\">
Divide the numbers in the table by 6.. .we observe that
Row 1 ....column A -> 0R1....Column B -> 0R3....Column C -> 0R5
Row 2 ....column B -> 1R5....Column C -> 1R3....Column D -> 1R1
Row 3 ....column A -> 2R1....Column B -> 2R3....Column C -> 2R5
Row 4 ....column B -> 3R5....Column C -> 3R3....Column D -> 3R1
we can classify the numbers as follows (when divided by 6)
even quotient R1 --> column A
even quotient R3/odd quotient R5 --> column B
even quotient R5/odd quotient R3 --> column C
odd quotient R1 --> column D
135 ÷ 6 = 22R3 --> even quotient R3 --> column B
one additional info that can be obtained from the quotient/remainder is
the row number for the given number is given by (quotient + 1)
cheers.