O-Level Additional Math

[Daddy]

Thanks dazzlego,


I still not very clear on the hightlight

In 2 hours, A,B,C can do 106/126 of the work
Thus, C need to do 20/126 = 10/63 of the work by himself
10/63 ÷ 1/9 = 10/7 hours

Can I write the answer 1.43hrs instead of 10/7hrs?

Thanks.

[Jtutor]

If I may add:

C needs to do (1-106/126) = 20/126 of the work which is remaining.
1/9 -> 1 hr
20/126 or 10/63 -> (10/63)/(1/9) * 1 hr = 10/7 hrs
Your answer can also be 1 3/7 hrs or 1.43 hrs (3sf)
Cheers!

[Daddy]

Thank Jtutor.

[Daddy]

Thank Jtutor.

[Daddy]

Thank Jtutor.

[Daddy]

Thank Jtutor.

[Daddy]

Thank Jtutor.

[Jtutor]

You are welcome!

[jackaaljaysen]

Hi all,


I am a student who will be taking Double Maths in Sec 3 next year.
Is A maths difficult? what can i expect in A maths next year?


Thanks and replies are appreciated

[jackaaljaysen]

Herbie:

Hi jie heng

Can show how you derive at the above answers?

Thanks!

Hi Herbie,

Have you tried the cross multiply method?

It is quite useful.

For e.g. your first qn, -6x^2+x+1

by cross multiply method, it should be done like this

3x 1 -2x
X
-2x 1 3x
_____________________________
-6x^2 1 x
This is because multiplying the different factorised terms will result in the original terms in the expression. If you expand the factorised term (3x+1)(-2x+1), you will get -6x^2+x+1.

You can try it with the other qn. If in doubt, feel free to pm me. :oops:
:celebrate: Cheers!