Q&A - PSLE Math

[mummyL]

Mr Tok left for Town A for Town B at 11.30am. He travelled at an average speed of 75km/h. At 12.15pm, Ms Selva left Town A for Town B, travelling on the same route at an average speed of 100km/h.

(a) At what time would Ms Selva overtake Mr Tok? Ans 2.30pm
(b)After Ms Selva had overtaken Mr Tok, she took another 2 hours to reach Town B.What
was the distance between Town A and Town B? Ans 425km

[tianzhu]

mummyL:

Mr Tok left for Town A for Town B at 11.30am. He travelled at an average speed of 75km/h. At 12.15pm, Ms Selva left Town A for Town B, travelling on the same route at an average speed of 100km/h.

(a) At what time would Ms Selva overtake Mr Tok? Ans 2.30pm
(b)After Ms Selva had overtaken Mr Tok, she took another 2 hours to reach Town B.What
was the distance between Town A and Town B? Ans 425km

Hi

Your question is pretty similar to the earlier one posted by peggy.

Please refer to page 700 of this thread.

http://www.kiasuparents.com/kiasu/forum/viewtopic.php?f=69&t=280&start=6990

Distance travelled by Mr Tok from 1130 to 1215 ------- ¾*75 --------- 56.25

100 – 75 ------- 25

56.25/25 ------- 2h 15 minutes

From 1215, add 2h 15 minutes

Mr Selva overtakes Mr Tok at 2.30 pm

Mr Selva travelled for 4h 15 minutes (2h 15 minutes + 2h)

Distance between A and B ------ 4.25*100 ------- 425 km

Best wishes

[Winx5015]

http://i50.tinypic.com/11tvsqu.jpg[/img%20[IMG]http://i47.tinypic.com/35k0cao.jpg\"> ]

[MathIzzzFun]

Winx5015:

http://i48.tinypic.com/10n7waq.png\">

hope this helps ...

http://i47.tinypic.com/aai33p.png\">

cheers.

[Essential]

Good Day Tianzhu, please help as not sure how to solve this question . At first Alvin had twice as many trading cards as Steven . after Alvin had given away 285 of his trading cards , Steven had twice as many trading cards as Alvin . How many trading cards did they have altogether at first ?

[tianzhu]

Essential:

Good Day Tianzhu, please help as not sure how to solve this question . At first Alvin had twice as many trading cards as Steven . after Alvin had given away 285 of his trading cards , Steven had twice as many trading cards as Alvin . How many trading cards did they have altogether at first ?

Hi

At first

Alvin:Steven ------ 2:1 ------ 4:2

Only Alvin had given away 285 cards. Steven’s number of cards stays the same before and after.

Hence, make the number of units for Steven the same.

In the end

Alvin:Steven ------ 1:2

3 units ------- 285

1 unit ------ 95

Number of cards they had at first ------- 6*95 -------- 570

Best wishes

[peggy]

Please assist.


There two bags of jelly beans labelled A and B. In bag A, there 470 red jelly beans and 480 green jelly beans. In Bag B, there are 350 jelly beans and 200 green jelly beans. Some red and green jelly beans from bag B are transferred to bag A. As a result, 60% of the jelly in bag A and 20% of those in bag B are red. How many red and green jelly beans are transferred from bag B to bag A ?

Thanks!

[kwcllf]

Tank A, base measuring 60cmx10cm and height 40cm is empty. Tank B, base measuring 50cmx20cm and height 36cm, is 1/3 filled with water. Water is poured into the two tanks at the same time at a rate of 1.2 litres per minute.


How long it take for the height of the water to be the same in both tanks?

Thanks!

[Winx5015]

Thanks MathIzzzfun.

[Winx5015]

Hi, can anyone help to solve this question.


In a hall, 3/5 of the pupils were girls. After some of the boys left the hall, the ratio of the number of girls to the number of boys increased to 5:2.
(a) If there were 36 boys left, how many pupils were there at first?
(b) At the beginning, the ratio of the number of girls who were in red T-shirts to those in black T-shirts was 4:5. 20% of the girls were in blue T-shirts. The number of girls in black T-shirts was the same as the number of boys in black T-shirts. If 20% of the remaining boys were in red T-shirts, how many boys were in blue T-shirts?

Thanks!