Hi

Thanks, l will try it out

n00bin4t0r:

All these are in rates (no of papers marked) per hour.
Let x be the number of days Wong takes to mark 36 papers.
Wong's rate = 36/x
Tan's rate = 36/(x+1)
Combined rate = (72x+36)/(x(x+1))
Combined duration = 2
Combined duration = 36/Combine rate
36/Combined rate = 2
... solve for x, remember to reject non-logical answers if there are 2 solution
Answer = x/36 (in papers per days) = ??? (in papers per minute)

I'm sure there are many ways to do this, but here's my thought process.
I have to find Wong's rate, so I let it be x.
Then, I have to get an equation where x is the only unknown so I can solve it.
A quick scan through & by gut feeling, its the equation that equates to 2.
So, I need the left-hand-side of that equation, the combined duration which requires the combined rate which in turn requires the individual rates of Tan & Wong.
So, I express Tan & Wong's rate in x, substitute to get their combined rate, then substitute to get combined duration and solve for x

Hi all Maths guru,


there is a sec3 maths qns (elearning) that I don't understd the steps and working given . The questions is below, I seek somebody who can provide me with easy explaination

Question

Mrs Tan takes 1 day more to finish marking the mathematics exam papers of all the 36 students in her class as compared to Mr Wong. If Mrs Tan marked the papers together with Mr Wong, both of them would complete the marking in 2 days. Find the time, in minutes, Mr Wong would take to mark a paper alone. Correct your answer to 3 sigificant figures

[A] 142 mins [B] 22.5 mins [C] 121 mins [D] 41.0 min

Hi


can any A level maths expert help on 9 (i) (a) with detail explaination if possible

http://www.numberskill.com/lessons-public/h2-math/2007-jcprelim/HCI/2007%20HCI%20Prelims%20Paper%201%20Questions.pdf

thanks in advance !

Hi,


My daughter Joey Yap, just completed her O Level is looking for young kids who are interested to learn piano.

She had obtained ABRSM Grade 8 this year and now pursuing her diploma and the examination will be next year April 11

Joey is passionate in Music and have experiences in piano accompanishment in church and other choir events.

We are staying in Bishan and do email or PM me at [email protected]

Christopher Yap
[email protected]

hi, can anyone help to solve this question for my daughter, it is o level A Maths question from acs


determine the values of p for which the line y = x - 2p is a tangent to the curve x^2+y^2 = 16p


Thanks

Oh yes, thank you very much.

hi,

Can someone help to solve this question

Mr Lai take X mins to carve a block of ice to swan, Mr Han takes 25 mins more to carve the same size of ice block to swan. if they carve the block of ice together only take 30 Mins to complete. derive all the above to the following equation
X^2-35X-750 = 0

small:

Hi fxchow,


HTH but I am not so sure on my answer for part (b).

a)
Given that 30% of the pupils in Sch A is 45 more than 40% of the pupils in Sch B.
0.3A - 45 = 0.4B --> x10

3A = 4B + 450 ----- equation (1)


If 10% of the pupils in Sch A leaves to join Sch B, there will be 200 more pupils in Sch A than Sch B
0.9A – 200 = 0.1A + 1B
0.8A = 1B + 200 --> x10

8A = 10B + 2000 ----- equation (2)


We will need to eliminate A to get B;

equation (1) x 8:
24A = 32B + 3600

equation (2) x 3:
24A = 30B + 6000

32B + 3600 = 30B + 6000
2B – 6000 – 3600
2B = 2400
1B = 1200

There are 1200 pupils in Sch B


b)
from equation (1) :

3A = 4 X 1200 + 450
3A = 4800 + 450
3A = 5250
1A = 1750 (100%)

The different between School A and School B is:
1750 – 1200 = 550

1750 = 100%
550 = 550/1750 x 100%
= 1100 / 35 %
= 31 3/7%


There are 31 3/7% percent less pupils in Sch B than Sch A

Hi, can anybody show us the working using modelling (blocks) Thanks !