Help please:

Jane has a box of counters; 50% are green, 25% are blue, and there are 11 white counters.
How many counters are there altogether?

Another badly worded question! If it said "Jane has a box of counters of 3 colours" it would be far clearer.

Anyway, assuming that there are only 3 colours, the 11 white counters represent the remaining 25%/quarter, and therefore 11 x 4 = 44 counters in total.

A bit vague as it does not say the box has three colours of counters in it! It should say 'the other 11 are white'.

What percentage must the whole box be?

What percentage is white?

Can you go from there? Come back if not.

[crossed post with S-A - great minds think alike re the question!]

Knowing there are 100% in total then white is 100-50-25 = 25%.

So if 25% (or one quarter) are white and total eleven counters then multiply by four to get 100% so 44 counters in total.

Again drawing a diagram and having more steps help if you are trying to explain to a student.

x-post with a faster typist ! oh and another one.

Thanks, makes sense now.

I wonder what would actually happen if a child in the exam stated that "the result cannot be determined as the question does not state if there are any other coloured counters apart from green, blue and white."

An extremely fast way of solving this is.....
First we analyse the question and quickly note down that there are three colours
and then we see that 50percent plus 25 percent equals to 75percent and as stated 11 white so 25percent is white therefore 25x25+50 equals 100percent

The problem is that it doesn't EXPLICITLY say there are only three colours - so the whole question is ambiguous.