Answer:
42%
Explanation:
The computation of the percentage is shown below:
Here we assume that there are 100 students
So according to the question
60% of the students would pack the lunch i.e. 60 students
And, 40% of the students buy a lunch i.e. 40 students
Now the students who pack the lunch they have 70% of cookie
So, 70% of 60 students = 42 students
Now the percentage is
= 42 students ÷ 100 students
= 42%