Asked by Anonymous

In a exam 80% students passed in accountancy, 85% paased in mathematic ,75% passed in both subject. If 45 students fail in boths subject than what is the total number of students?
Answered by Steve
the number who passed either or both is

.80+.85-.75 = 0.90

So, 10% of x students failed both:

45 = 0.10x
. . .