Q&A - PSLE Math

[isetan]

Hi, can someone help with this question:


Some workers arranged chairs in 18 short rows and 7 long rows. Each long row had 32 more chairs than each short row. Half of the chairs were arranged in long rows while 3/7 of the chairs were arranged in short rows. The remaining chairs were stacked in a corner.
(a)What fraction of the chairs were stacked in a corner?
(b)How many chairs were arranged in rows?

TIA.

[atutor2001]

isetan:

Hi, can someone help with this question:


Some workers arranged chairs in 18 short rows and 7 long rows. Each long row had 32 more chairs than each short row. Half of the chairs were arranged in long rows while 3/7 of the chairs were arranged in short rows. The remaining chairs were stacked in a corner.
(a)What fraction of the chairs were stacked in a corner?
(b)How many chairs were arranged in rows?

TIA.

Let me exercise my decaying brain

1/2 = 7/14 of total chairs were in 7 long rows
3/7 = 6/14 of total chairs were in 18 short rows
(a) 14/14 - 7/14 - 6/14 = 1/14 of total chairs were stacked in a corner

If the total no. of chairs was divided into 14 parts,

7 parts (7/14) of total chairs = chairs in 7 long rows
1 part (1/14) of total chairs = chairs in 1 long row
1 part (1/14) of total chairs = chairs in 1 short rows + 32

6 part (6/14) of total chairs = chairs in 18 short row
but
1 part (1/14) of total chairs = chairs in 1 short rows + 32
6 part (6/14) of total chairs = chairs in 6 short row + 192 [note : 32 x 6 = 192]

So Chairs in 18 short row = Chairs in 6 short row + 192
so Chairs in 12 short row = 192
so Chairs in 1 short row = 192/12 = 16 chairs

1 part (1/14) of total chair = Chairs in 1 short row +32 = 16 + 32 = 48
Total chairs arranged in rows = 14 parts = 48 x 14 =672

[isetan]

atutor2001:

isetan:

Hi, can someone help with this question:


Some workers arranged chairs in 18 short rows and 7 long rows. Each long row had 32 more chairs than each short row. Half of the chairs were arranged in long rows while 3/7 of the chairs were arranged in short rows. The remaining chairs were stacked in a corner.
(a)What fraction of the chairs were stacked in a corner?
(b)How many chairs were arranged in rows?

TIA.

Let me exercise my decaying brain

1/2 = 7/14 of total chairs in 7 long rows
3/7 = 6/14 of total chairs in 18 short rows
(a) 14/14 - 7/14 - 6/14 = 1/14 of total chairs were stacked in a corner

If the total no. of chairs is divided into 14 parts,

7 parts (7/14) of total chairs = 7 long rows
1 part (1/14) of total chairs = 1 long row
1 part (1/14) of total chairs = 1 short rows + 32

6 part (6/14) of total chairs = 18 short row
but
1 part (1/14) of total chairs = 1 short rows + 32
6 part (6/14) of total chairs = 6 short row + 192

So 18 short row = 6 short row + 192
so 12 short row = 192
so 1 short row = 192/12 = 16 chairs

1 part (1/14) of total chair = 1 short row +32 = 16 + 32 = 48
Total chairs in rows = 14 parts = 48 x 14 =672

Thanks atutor2001,

Your brain is not decaying but rather an active one. Thanks for the ans.

[MathIzzzFun]

isetan:

Hi, can someone help with this question:


Some workers arranged chairs in 18 short rows and 7 long rows. Each long row had 32 more chairs than each short row. Half of the chairs were arranged in long rows while 3/7 of the chairs were arranged in short rows. The remaining chairs were stacked in a corner.
(a)What fraction of the chairs were stacked in a corner?
(b)How many chairs were arranged in rows?

TIA.

Hi

..MD & units approach...

http://i50.tinypic.com/2hnc6fr.png\">

cheers.

[isetan]

MathIzzzFun:

isetan:

Hi, can someone help with this question:


Some workers arranged chairs in 18 short rows and 7 long rows. Each long row had 32 more chairs than each short row. Half of the chairs were arranged in long rows while 3/7 of the chairs were arranged in short rows. The remaining chairs were stacked in a corner.
(a)What fraction of the chairs were stacked in a corner?
(b)How many chairs were arranged in rows?

TIA.

Hi

..MD & units approach...

http://i50.tinypic.com/2hnc6fr.png\">

cheers.

Thanks mathizzzfun!

[atutor2001]

isetan:

Thanks atutor2001,

Your brain is not decaying but rather an active one. Thanks for the ans.

Sorry, confirmed chopped chopped that my brain is decaying. My answer is wrong. What I have given was the total number of chairs and not the \"chairs arranged in row\".

So the correct answer is :
1 part (1/14) of total chair = 1 short row +32 = 16 + 32 = 48
Total chairs in rows = 14 - 1=13 parts = 48 x 13 =624

MathIzzFun's answer is the correct one. :salute:

[jarenchuatw]

Need help in solving these 2 questions:


Q1 Hock and Mei live in the same block of flat. There are 84 steps from the first level to the foruth level. Hock lives in the first level. How many steps must he climb to get from his flat to Mei’s flat which is on the 8th level (There are the same number of steps between each level).

Note: We got the answer as 168 but that was wrong - the correct answer is 196 (why huh?)

Q2 pls refer to the image attached

[Michaelia0816]

jarenchuatw:

Need help in solving these 2 questions:


Q1 Hock and Mei live in the same block of flat. There are 84 steps from the first level to the foruth level. Hock lives in the first level. How many steps must he climb to get from his flat to Mei's flat which is on the 8th level (There are the same number of steps between each level).

Note: We got the answer as 168 but that was wrong - the correct answer is 196 (why huh?)

Q2 pls refer to the image attached

For Q1 , mine is same as your, you're correct, it took 21 steps to get to another level, so times 8 is equal to 168.

[kwcllf]

Michaelia0816:

jarenchuatw:

Need help in solving these 2 questions:


Q1 Hock and Mei live in the same block of flat. There are 84 steps from the first level to the foruth level. Hock lives in the first level. How many steps must he climb to get from his flat to Mei's flat which is on the 8th level (There are the same number of steps between each level).

Note: We got the answer as 168 but that was wrong - the correct answer is 196 (why huh?)

Q2 pls refer to the image attached

For Q1 , mine is same as your, you're correct, it took 21 steps to get to another level, so times 8 is equal to 168.

Each level has 28 steps (84/3 not 84/4) although there are 4 levels.

To climb up to Mei's flat on the 8th floor ---> 28 steps x 7 = 196 steps

Every 2 levels, there are only 28 steps. You only need to climb 1 level to reach the second level.
So, for the 8th level, multiply by 7, not 8

[Spongy]

Hi I need help in a question. :thankyou:


1. Charlie and Diana had some stamps. Charlie had 70% of what Diana had at first. Charlie then gave Diana 60% of what he had. As a result, Diana had 912 more stamps than Charlie. How many stamps did Charlie have at first?