hope this helps

Assume Ahmad is A, Devi is D and Betty is B.A+D=250,A+7D=658

6d is 408,d is 68, a is 250-68

Thanks a lot !!

Align Ahmad since that is common. Compare Devi and Betty.

Thanks Yueh Mei !! Got it !!

250-[(658-250)÷(7-1)]

May I ask which level is this question for?

6 units --- 658-250= 408 1 unit -- 408/6=68 Ahmad-- 250-68=182

This is for P5 Agnes Woon

Thank you.

Thanks adrian

For $30 and $50 why do you multiply 12u by 12 and 3u by 12?

If we don't, you'll get 5u/12=0.4166666666..... This is not helpful.

There is a clue in the question that says there were four more $5 notes than $2 notes.

I actually think the answer is different from the image posted above. See attached...I hope this helps!

For p5, dun think they are taught to use algebra as yet

I hv a different answer.

Sorry, I didn't know about the no-algebra rule! I'm over here in the US. I'm pretty sure I had the right answer. Attached is a solution using the model method. The key is to recognize at the top of my picture that if you add quantity 24 to the three sets of a's in the first bar, then you have the same quantity as that of the the seven sets of b's in the second bar. From there the numbers can be worked out by substitution.

Hi Gabe Lucas, you are kind enough to offer ur advise. Algebra are taught but at a later stage

No problem, Kim Wong Just wondering...would my second picture be considered too much algebra for this solution? Just curious.

In Singapore national schools, Algebra is taught at Primary 6 where the students are generally between 11+ & 12+ years old.

Testing ....

Pieter Cronje, the question states that there were 4 more $5 notes than $2 after the exchange, not equal number of notes.

Vei Li Soo you are right! My mistake! Did not read qn correctly!

Using the Model Method...

4 more $5 notes than $2 . Meaning 4 plus and not 4 times....

Integrating Model Method with algebra...

Thks all....much appreciated

This question is hard to solve without algebra, and the drawing of models can be quite cumbersome. One way to do it without symbolic "algebra" is to use the concept of ratio as follow (with explanation):

Here's a possible solution. See if you can make sense of it.