Comments on: Algebra – Who’s the Lazy Bugger?

By: Recabyte

Recabyte — Sat, 28 Feb 2009 03:37:17 +0000

Simplify the problem. Look from doing 2 set of project instead.

1 project for B and J = 10 hrs
2 projects for B and J = 20 hrs

if 1 project for B = 15 hrs
then 1 project for J = 20 - 15 = 5 hrs.

By: Smiley:)

Smiley:) — Fri, 13 Feb 2009 15:03:53 +0000

I don't understand why 24- x= x-12 then how to get 36?

By: miy0k0

miy0k0 — Sun, 21 Sep 2008 00:28:31 +0000

are those PSLE questions?erm...i dun understand the question Postman: How are your 3 daughters, Mr Lim?
Mr Lim: They are fine. Thank you.
Postman: How old are they now?
Mr Lim: The product of their 3 ages is 36. The sum of their ages is the same as my house number.
Postman: Err.. I can’t figure it out.
Mr LIm: Well, my eldest daughter is waiting for her letter now.
Postman: Oh, I got it. Thanks

By: brokenshardz

brokenshardz — Fri, 19 Sep 2008 14:28:57 +0000

I got the ans for the above qn liao... solved in 5 mins....

the 2nd faster solution:
Yvonne + Rachel = From A (Starting pt) to B (Ending pt). 10 mins
Rachel = From B to A. 1 min
George + Rachel = From A to B. 7 mins
Rachel = From B to A. 1 min
Ben + Rachel = From A to B. 2 mins
Total time spent= 10 + 1 + 7 + 1 + 2 = 21 mins

Fastest solution:
Ben + Rachel = From A to B. 2 mins
Rachel = From B to A. 1 min
Yvonne + George = From A to B. 10 mins
Ben = From B to A. 2 mins
Ben + Rachel = From A to B. 2 mins
Total time = 2 + 1 + 10 + 2 + 2 = 17 mins.

Tada!

By: ashton

ashton — Fri, 19 Sep 2008 09:43:43 +0000

Well Miss Loi, while you and your devotees are having fun with this P4 question, let me pose just one more. So that those who are really keen, can have more fun over the weekend. (evil laugh....)

Four friends need to cross a bridge.
They start on the same side of the bridge.
A maximum of two people can cross at any time.
It is night and they have just one lamp.
People that cross the bridge must carry the lamp to see the way.
A pair must walk together at the rate of the slower person:

* Rachel: - takes 1 minute to cross

* Ben: - takes 2 minutes to cross

* George: - takes 7 minutes to cross

* Yvonne: - takes 10 minutes to cross

The second fastest solution gets the friends across in 21 minutes.
The fastest solution takes 17 minutes. Can you work out how it is done?

By: Miss Loi

Miss Loi — Thu, 18 Sep 2008 17:22:40 +0000

On behalf of The Temple, Miss Loi would like to thank you Ashton for making her miss her Channel 55/255 TVB drama just now

This is exactly the sort of question which a P4 kid will answer with ease but on the other hand will leave an adult hopelessly stumped.

In any case, probably being a P4 kid at heart, Miss Loi believes she has the full answer and explanation (and just to prove that she really does know: you'll just have to imagine you're the postman who's supposed to know it all - right? RIGHT? ) but she shan't reveal it now coz she would like to pose this question to others in the meantime

Wow the answer really JUMPED right out from the screen! Hahaha ...

By: ashton

ashton — Thu, 18 Sep 2008 07:21:40 +0000

Clap! Clap!

By: kiddo

kiddo — Thu, 18 Sep 2008 06:58:16 +0000

Thanks Ashton. Are their ages are 2, 2 and 9?

By: ashton

ashton — Thu, 18 Sep 2008 06:22:00 +0000

Why don't you list down all the possible combinations?

Product Sum
1 1 36 = 38
1 2 18 = 21
1 3 12 = 16
1 4 9 = 14
1 6 6 = 13
2 2 9 = 13
2 3 6 = 11
3 3 4 = 10

Can you see something there?

By: kiddo

kiddo — Thu, 18 Sep 2008 05:55:51 +0000

We deduce house number is not 11 (= 2 + 3 + 6),
14 (= 1 + 4 + 9), 16 (= 1 + 3 + 12) or 21 (= 1 + 2 + 18)
but does that help?

The last reply that enlightened the postman is the statement that stumps me. What's the link between the eldest daughter's 'age' & 'letter'?