Question #3770d

1 Answer
Apr 26, 2017

I suspect there may be something wrong with this question.
I have invited someone specific to look at this question.

Explanation:

#color(blue)("First interpretation of the question: This one fails")#

The total count of the 'sample population' we are considering is

#2/3+2/5# of the whole #= [(2xx5)/(3xx5)]+[(2xx3)/(5xx3)] = 10/15+6/15#

#= 16/15# of the whole

Note that you can not have more people with lunch than there are people in the whole. #color(red)("Consequently this model is wrong")#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Second interpretation of the question: This one should work")#

#color(green)("Of the people that brought lunch ("2/3" of the whole) ")#
#color(green)(2/5" bought lunch")#

Proportion(1)
So #2/5xx2/3=5/15# of the whole population paid for their lunch

Proportion(2)
So those that did not pay for their lunch is

#(1-2/5)xx2/3= 2/5=6/15# of the whole population.

The proportion that did not pay for their lunch is higher than those that did. As implied in the question.

The ratio for this is
#"did not pay : paid" ->6/15:5/15 #

Presenting the ratio in #color(red)("fractional FORMAT")#

#("did not pay")/("paid")->6/5color(red)(" note that ratio is not a fraction")#

As a fraction we have #6/(6+5) = 6/11 # did not pay

As a fraction we have #5/(6+5)=5/11 # did pay

So complying with the wording requirement of the question we have:

#6/11-5/11=1/11# more of the student brought (did not pay)