
By: pearldyn (offline) Monday, April 12 2010 @ 08:29 AM CDT (Read 2039 times)



pearldyn 
Hello all,
Can anybody help me with this one?
Question number. 41
An MRT train was 2/5 full of passengers.
At the first station, 1/2 of the passengers alighted and 17 people boarded the train.
The train is now 1/4 full. How many passengers were there on the train at first?
Thanks in advance!

Junior
Registered: 06/17/09 Posts: 30





By: pearldyn (offline) Monday, April 12 2010 @ 10:03 AM CDT



pearldyn 
Can anyone help me on this?
There are 380 children at the Children's Carnival.
3/7 of the boys and 2/3 of the girls are watching the magic show.
The number of girls who are not watching the magic show is equal
to the number of boys who are not watching the magic show.
How many boys are at the Children's Carnival?

Junior
Registered: 06/17/09 Posts: 30





By: pearldyn (offline) Monday, April 12 2010 @ 10:08 AM CDT



pearldyn 
Quote by: pearldynHello all,
Can anybody help me with this one?
Question number. 41
An MRT train was 2/5 full of passengers.
At the first station, 1/2 of the passengers alighted and 17 people boarded the train.
The train is now 1/4 full. How many passengers were there on the train at first?
Thanks in advance!
This question has been answered, sorry!

Junior
Registered: 06/17/09 Posts: 30





By: kohkah (offline) Tuesday, April 13 2010 @ 02:23 AM CDT



kohkah 
pearldyn
Can anyone help me on this?
There are 380 children at the Children's Carnival.
3/7 of the boys and 2/3 of the girls are watching the magic show.
The number of girls who are not watching the magic show is equal
to the number of boys who are not watching the magic show.
How many boys are at the Children's Carnival?
4/7 of boys = 1/3 of girls
redraw the model, replacing every 1 block of girl by 4 block of boys. Something like substituting in alegbra.
boys 1234567
girls 123456789101112
therefore, a total of 19 blocks = 380 children. each unit of block is = 20,
boys has 7 units, which is 140 boys.

Newbie
Registered: 12/31/06 Posts: 7





By: yeoky (offline) Tuesday, April 13 2010 @ 05:10 AM CDT



yeoky 
Quote by: pearldynHello all,
Can anybody help me with this one?
Question number. 41
An MRT train was 2/5 full of passengers.
At the first station, 1/2 of the passengers alighted and 17 people boarded the train.
The train is now 1/4 full. How many passengers were there on the train at first?
Thanks in advance!
1/4 ==> 1/5+17
4/4=1 ==> 4/5 +68
5/5 ==> 4/5 +68
1/5 ==> 68
2/5 ==> 134 (Answer)
Check,
2/5 ==>134/340
1/5==>68/340
68+17=85
85/340=1/4
Hope it helps.

Newbie
Registered: 04/12/10 Posts: 1





By: tanhuimin (offline) Thursday, April 15 2010 @ 04:31 AM CDT



tanhuimin 
Question number. 41
An MRT train was 2/5 full of passengers.
At the first station, 1/2 of the passengers alighted and 17 people boarded the train.
The train is now 1/4 full. How many passengers were there on the train at first?
P4 is expected to solve this question by model drawing.
From model drawing, we can tells that
1 units > 17
8 units > 17 x 8 = 136
Answer : 136 passengers at first.
[img]

Junior
Registered: 12/31/06 Posts: 18





By: pearldyn (offline) Thursday, April 15 2010 @ 06:57 AM CDT



pearldyn 
Thanks HuiMin. Your model does really makes me understand it much clearer.
How about trying to solve the Carnival question?

Junior
Registered: 06/17/09 Posts: 30





By: tanhuimin (offline) Thursday, April 15 2010 @ 10:32 PM CDT



tanhuimin 
There are 380 children at the Children's Carnival.
3/7 of the boys and 2/3 of the girls are watching the magic show.
The number of girls who are not watching the magic show is equal
to the number of boys who are not watching the magic show.
How many boys are at the Children's Carnival?
In fact KohKah already solved the problem.
This question for P4 need to be solved by drawing model too.
Not watching show, Boy > 4/7 of total no. of boys (a)
Not watching show, Girl > 1/3 of total no. of girls (b)
since (a) and (b) has to be the same value, we show it in the model drawing
From the model,
Total no. of the small unit (with pink tick) = 7 + (4 x 3) = 19
1 unit > 380 / 19 = 20
Total no. of boys = 20 x 7 = 140

Junior
Registered: 12/31/06 Posts: 18



