Q&A - PSLE Math

[MathIzzzFun]

whitety:

Hi,

I need help on 3 speed qns:


2) Jay took 10min to walk from the train station to the shopping mall at a uniform speed. Kay took 15min to walk from the shopping mall to the train station at a uniform speed. Both of them started at 4.23pm. At what time did Jay and Kay pass each other along the way?



Thanks!

Hi

alternate approach for Q2 using time & speed/distance ratio.
Q2.
Time ratio of Jay : Kay --> 10 : 15 = 2 : 3
Speed (or distance ratio) of Jay : Kay --> 3u : 2u, when they meet, Jay completes 3u of distance, Kay completes 2u of distance. Total distance = 5u
Time taken by Jay to complete 3u --> 3/5 x 10 min = 6min
meeting time --> 4.23pm + 6 min = 4.29 pm

cheers.

[MathIzzzFun]

whitety:

Hi,

I need help on 3 speed qns:

3) Ace and Nash started jogging at the same speed along a track. When Ace completed 5/6 of the distance, Nash had only completed 3/8 of the distance. Ace's average speed was 88m/min faster than Nash's. What was Nash's average speed in m/min?

Thanks!

Hi

Q3.
Total distance --> 24 u
distance completed by Ace --> 20 u
distance completed by Nash --> 9 u
speed of Ace : Nash --> 20u : 9u
11u --> 88m/min
Nash's speed = 9/11 x 88 m/min = 72 m/min

cheers.

[MathIzzzFun]

Tiramisu Coco:

Hi, need help for this question.


Tom only has watermelons. Sam only has oranges. They gave each other half of their fruits. Tom sold 9 watermelons and Sam sold 85 oranges. In the end the ratio of  watermelons to oranges for Tom and Sam is 1:10 and 1:5 respectively. How many watermelons did Tom have at first?

Thanks.

Hi

here's a similar question ... http://www.flickr.com/photos/62167097@N02/6943541872/in/photostream

you can use the same approach to solve.

cheers.

[whitety]

Hi small & MathIzzzFun,


Thank you very much!

[Neat]

Hi.


Please assist with the following question:

A gallery owner had three boxes, A, B and C, containing a total of 1500 vintage stamps. The number of vintage stamps in Box A to the total number of vintage stamps was 3:10. He sold 330 vintage stamps from Box B and sold 1/3 of the vintage stamps in Box C. The number of vintage stamps left in Box B to the number of vintage stamps left in Box C was 3:1. How many vintage stamps were there in Box B at first?

Thanks

[small]

Neat:

Hi.


Please assist with the following question:

A gallery owner had three boxes, A, B and C, containing a total of 1500 vintage stamps. The number of vintage stamps in Box A to the total number of vintage stamps was 3:10. He sold 330 vintage stamps from Box B and sold 1/3 of the vintage stamps in Box C. The number of vintage stamps left in Box B to the number of vintage stamps left in Box C was 3:1. How many vintage stamps were there in Box B at first?

Thanks

Hi,

HTH.

10units = 1500
7units = 1050

Number of stamps in Box B and Box C at first is 1050

Given that 2/3 of the vintage stamps left in Box C

Now
B : C ----- 3 : 1
B : C ----- 6p : 2p

At first
B : C ----- 6p+330 : 3p

9p + 330 = 1050
9p = 720
1p = 80

Number of stamps in Box B at first ----- 6p + 330 = 810

[small]

whitety:

Hi small & MathIzzzFun,


Thank you very much!

You are welcome whitety.

[Neat]

small:

whitety:

Hi small & MathIzzzFun,


Thank you very much!

You are welcome whitety.

Thank You very much.
:thankyou:

[Neat]

Hi.


I have another question:

Ben, Ken and Jen received a sum of money from their grandparents. Ben received 50% more money than Ken. Ben and Ken each gave 30% of their money to Jen. As a result, Jen’s money increased by 20%. If Jen had $760 more than Ken in the end, how much did Jen receive from his grandparents?

Thanks

[MathIzzzFun]

Neat:

Hi.


I have another question:

Ben, Ken and Jen received a sum of money from their grandparents. Ben received 50% more money than Ken. Ben and Ken each gave 30% of their money to Jen. As a result, Jen's money increased by 20%. If Jen had $760 more than Ken in the end, how much did Jen receive from his grandparents?

Thanks

Hi

Ben --> 30 units, 30% --> 9u, left --> 21u
Ken --> 20u units, 30% --> 6u, left --> 14u
Total given to Jen --> 15u
20% of Jen --> 15u
120% of Jen --> 90u, 100% of Jen --> 75u

Jen had $760 more than Ken in the end,
90u-14u = 76u --> $760
1u --> $10
75 x $10 = $750

Jen received $750.

cheers.