Q&A - PSLE Math

[raghupavithra]

The average height of 2 girls is 1.50m. The difference in their height is 0.4m. What is the height of the taller girl?


1.10
1.30
1.54
1.70
pls help

[tianzhu]

raghupavithra:

The average height of 2 girls is 1.50m. The difference in their height is 0.4m. What is the height of the taller girl?


1.10
1.30
1.54
1.70
pls help

Hi

2*1.5 -----3

3-0.4 ----- 2.6

2.6/2 ------ 1.3

1.3 + 0.4 ------ 1.7 (ans)

Best wishes

[tianzhu]

Hi


Hope this helps.

Best wishes.

http://farm7.static.flickr.com/6177/6160679750_ff917d0516_z.jpg\">

[zsqchx]

Please help me to solve Q 16 of Henry park 2011


Mr Lee took 7 hours to tavel from town A to Town B while Mr Wong took 8 hours to travel from Town B to Town A. Both of them did not change their speed throughout the journey. Both of them started off at the same time and moved towards each other. 3 hours later, they were 110 km apart. what was the speed Mr Lee was driving?

Thanks

[tianzhu]

zsqchx:

Please help me to solve Q 16 of Henry park 2011


Mr Lee took 7 hours to tavel from town A to Town B while Mr Wong took 8 hours to travel from Town B to Town A. Both of them did not change their speed throughout the journey. Both of them started off at the same time and moved towards each other. 3 hours later, they were 110 km apart. what was the speed Mr Lee was driving?

Thanks

Hi

Good Morning.

As in any question on “Speed”, it’s helpful to draw a simple diagram showing the relationships between two motorists.

Use a common multiple of 56 (7 and

Mr Lee
1h ------ 8 units

Mr Wong
1h ------7 units

In 1h they travelled 15 units
In 3h, they travelled 45 units.

56 – 45 ------11
11units ------ 110

1 unit ------ 10
8 units ------80

Mr Lee ------- 80km/h

Best wishes

[zsqchx]

tianzhu:

zsqchx:

Please help me to solve Q 16 of Henry park 2011


Mr Lee took 7 hours to tavel from town A to Town B while Mr Wong took 8 hours to travel from Town B to Town A. Both of them did not change their speed throughout the journey. Both of them started off at the same time and moved towards each other. 3 hours later, they were 110 km apart. what was the speed Mr Lee was driving?

Thanks

Hi

Good Morning.

As in any question on “Speed”, it’s helpful to draw a simple diagram showing the relationships between two motorists.

Use a common multiple of 56 (7 and

Mr Lee
1h ------ 8 units

Mr Wong
1h ------7 units

In 1h they travelled 15 units
In 3h, they travelled 45 units.

56 – 45 ------11
11units ------ 110

1 unit ------ 10
8 units ------80

Mr Lee ------- 80km/h

Best wishes

Hi Tianzhu,

Thank you for your help

[tianzhu]

htn:

tianzhu

thanks.

Hi

You're welcome.

Best wishes

[tianzhu]

P.KH:

Dear tianzhu , thanks a lot for your quick reply .. It was really helpful . 

Hi

You're welcome.

Best wishes

[tianzhu]

zsqchx:

Hi Tianzhu,

Thank you for your help

Hi

You're welcome.

Best wishes

[kavisuresh]

Pls help in solving these questions from 2009 prelims.

1. A rectangular tank with dimesnions 130cm by 100cm by 210cm was 30% filled with water. 8 identical pails of water, completely filled , were scooped out of it from it and this resulted in a drop of the water level to 38cm. The remaining amt of water was transferred into a cubical tank containing 39l of water. The water was then drained out through a tap at the bottom of the cubical tank at 13l per minute. a) what is the capacity of each pail ? b) How long did it take to drain water from cubical tank completely ?

2.A car and a coach travelled from town A to town B. The coach left Town A at 0648 and it took 5h to reach town B. The car started 30minutes later than the coach and it took 4hours to reach town B. At what time did the car catch up with the coach ?

3. Aaron and kumar took part in a 24km marathon. Aaron ran half the distance at a speed of 10km/h and jogged the rest of the way at a speed of 8km/h. Kumar ran half of his total time at 12km/h and jogged the rest of the time at 6km/h. If they started the marathon at 8am, at what time would each of them finish ?

4. 65% of the animals on a farm were cows and the rest were goats. When 240 more cows and goats were added to the farm the percentage of cows increased by 20% and the number of goats doubled. How many goats were there on the farm at first ?

5. There are some black and white marbles in a bag. If 20black marbles are removed from the bag, the total number of marbles left will be 7times the number of black marbles left. If 50 white marbles are removed from the bag, the total number of marbles left will be 5times the number of black marbles left. How many marbles are there in the bag ?

Thanks you.