Answer:510 students
Explanation: given that total student is 850
And Of every 10 student 6 will have to sit for a refresher math course
Hence the number that will need a refresher math course will be (850/10)*6= 510
Or better still to better understand this let's use the crossing multiplication method
of 10 student 6must do a refresher math then
Of 850 students x must do a refresher math
Cross multiplying we have
X=(850*6)/10=510 students
