Q&A - PSLE Math

[MathIzzzFun]

pensiveowl:

atutor2001:

[quote=\"pensiveowl\"]Hi, could someone pls help us work this out:


http://www.positivelyquit.org/images/q17.jpg\">

Thanks

Not sure if my mind is still working as it appears to be very tedious to get the shaded area if area A is not given.

Finding area A alone is a nightmare to me. I would need to use Pythagoras theorem just to find area A. Hope some math guru can come out with an easy solution

Thanks for trying.. just fyi, the answers are supposed to be:
(a) 484pi + 3872 - 2A
(b) 132pi[/quote]Hi

http://i53.tinypic.com/9kwmqp.jpg\">

(leaving the construction lines in the figure cos quite a task to remove them )

cheers.

[pensiveowl]

Hi


http://i53.tinypic.com/9kwmqp.jpg\">

(leaving the construction lines in the figure cos quite a task to remove them )

cheers.[/quote]


Wah! thanks MathIzzzFun

[MathIzzzFun]

pensiveowl:

Hi


http://i53.tinypic.com/9kwmqp.jpg\">

(leaving the construction lines in the figure cos quite a task to remove them )

cheers.


Wah! thanks MathIzzzFun

u r welcome.

Happy National Day to all !

cheers.

[bobsg01]

IMTRYINGSTUFF:

bobsg01:

Need help to find Angle a, b, d, e


Thanks in advance for your help.

http://i55.tinypic.com/oa645d.jpg\">

Is is 239˚???

180-65(big triangle)=115˚(a and b)
180-56(DFC)=124˚(e and d)
124+115=239˚(a and b and d and e)

Yes IMTRYINGSTUFF you are correct.

Thank you and Happy National Day. :rahrah: :rahrah: :rahrah:

[tianzhu]

Belle2011:

Dear all,

I need some help, please.

Ahmad and Halim together took 5 days to paint their house. If Ahmad and Halim work together for 2 days, followed by Ahmad working alone for 8 days, Halim will take 1 more day to complete the remaining work. How long will Ahmad take to paint the house all by himself?

Thank-you.

Hi Belle2011

This question touches on “Rates”.

There is more than one way to solve it.
One possible solution is:

When Ahamd and Halim work together, they can paint their house in 5 days.
In 1 day, they can paint 1/5 of their house or 1 unit.

Hence, 1 day of Ahmad + 1 day of Halim ----- 1 unit

In 2 days, they can paint 2/5(2 units) of their house, this means 3/5(3 units) of their house is left unpainted.

8 days of Ahmad + 1 day of Halim ----- 3 units
1 day of Ahmad + 1 day of Halim ----- 1 unit

Therefore, 7 days of Ahmad ----- 2 units
17.5 days ----- 5 units(whole house)

Ahmad took 17.5 days to paint the house all by himself.

Best wishes

[atutor2001]

pensiveowl:

Thanks for trying.. just fyi, the answers are supposed to be:
(a) 484pi + 3872 - 2A
(b) 132pi

Thank you for the answer. The question is not properly worded. It should be \"leave your answer in terms of pi and A\".

[alrama]

MathIzzzFun:

alrama:

Kailing and jim had a total of $63. Kailing gave 0.3 of her share to jim. Jim then gave 1/3 of the total amount of money he had to his brother. In the end, all the three children had the same amount of money. How much money did kailing have at first? ans:36. Can anyone explain?

Hi

hope this helps

http://www.flickr.com/photos/62167097@N02/6020796670/in/photostream/
thks for the ans. :rahrah:

cheers.

[Cheerfuldad]

Hi,


Q. mei ing and Raja started on a 36km cycling trip at the same time. They cycled at the same speed fit the 12 mm. For the remaining 24km, Meiling cycled at a faster speed. She arrived at the finishing point 10 minutes before Raja who was 4km behind her. Raja did not change his speed throughout the trip and he completed the trip at 11 10.

A) At what time did the trip start?

B). What was Meiling’s average speed for the remaining 24km of the trip in m/min?

TIA.

[Cheerfuldad]

Hi,


PL help.

Q. Sally baked some cookies to sell. 3/4 of them were chocolate cookies and the remaining were almond cookies. After she sold 5/6 of chocolate cookies and 210 almond cookies, she had 1/5 of the cookies left. How many cookies did she sell?

TIA.

Regards

[blitz]

Help please.

Tracy counted the number of 10cents coins, 20cent coins and 50cents coins in her piggy bank. The number of 10c coins was 24 more than the number of 50c coins. After spending 3/5 of the 10c coins, 1/4 of the 20c coins and 18 50c coins, she had an equal number of 10c and 20c coins. The number of 50c coins now formed 40% of the remaining number of coins.

(a) How many 10c coins did Tracy have at first?
(b) How much did she spend in all?