thanks for the detailed workings, really appreciate it! i do understand but at P6 level, is this the only way?

Unfortunately, for this particular question, I could not find a simpler solution other than algebra to explain this.
Maybe if I have another solution I will come back to post it.
I have tried using Ratio to no avail and Trail & Error takes too long.
The algebra here involves forming your own equation which at a P6 level can be a little difficult to understand. But once the concept is understood, you will find that many tough questions can be approached in a similar fashion.

ahh i see, i used ratio to organise the fractions. i also thought of using algebra but was checking if there’s an easier way. thanks for your replies though!

Yes, because it involved subtraction, it is difficult to break it down to ratio and quantify them.

It is very helpful to have a strong foundation in Algebra as early as possible in any case. Algebra will be a very big part of secondary school and much more complicated.