30 students took an exam. 10 of the students that took the exam failed so 20 students who took the exam passed.
The fraction
represents the number of students who passed it out of all the students that took the exam.
The fraction
can be reduced to
by dividing both the numerator and denominator by the greatest common factor of 20 and 30 which is 10.
2 ÷ 3 = 0.66666666666667
0.66666666666667 × 100 = 66.666666666667%
66.666666666667% of the students passed the exam.