If Su Ann were to win all 12 rounds, she would have 60points. For every game that she didn't win, you minus 3points. In order to have 45, you would have to minus 15points which is 5 games. To check back, Su Ann won 7 (35points) and lost 5 (5 x 2 = 10points) = 45points

Thank you Vincent Ong

Draw before and after diagrams then look for equal units that represent a certain quantity.

Thanks for showing me the models! But I don't understand the after model. How do we explain the 342 for Ryan?

Ryan was given $342, so the dotted line from the Ryan's blue bar to the end of his green bar shows the added 342.

Why 2 -15 =1p need to times 3?

So that you can get 3p, which you can use to match/equate with the other equation from 'black'

Ok thks

The answer in the answer sheet is 50....not sure.

The total number of balls is 70 + 90 = 160

Total number of marbles is 100 + 20 = 120. in the end 40% of A and 70% of B are balls. 60% of A and 30% of B are marbles. You can then use simultaneous equations. 40% A + 70% B = 160 balls 60% A + 30% B = 120 marbles then need to make a or b the same. we will make A the same by multiplying the first equation by 3 and the second equation by 2 thus 120% A + 210 % B = 480 and 120% A + 60% B = 240

subtract the two equations 150% of B = 240 thus 100% of B equals 140 therefore in the end B has 160 items. it had 110 items at first (90 + 20) thus 160 - 110 = 50 were transferred

Great Peter Back. Thanks a lot.

Yes, simultaneous equations are taught in P5 itself...This question can also be solved by units and parts method.

Units and parts might be common in assessment books but looking at the last 2 years of psle questions, it's not a necessary skill.

Hi, I thought I'd share my solution using simultaneous (in fractions)

This is in units and parts method.

Both are taught.

Simultaneous disguised as parts and units. If the problem can only be solved using simultaneous equation, then I'm pretty sure it's not within the syllabus, hence such question should not be in the exams.

I hate to tell you that these sort of questions are common in school exam papers. They even get a little harder than this.