To pass science, a student must earn at least a grade of 70. How many students failed this science class?

Answer:
7 students.
Step-by-step explanation:
To pass science, a student requires at least 70 grades so students who scored below 70 will be failed.
From the given bar chart we can calculate the number of students who scored below 70 grades
Students who earned 50 - 59 = 2
Students who earned 60 - 69 = 5
Therefore, number of students who failed were
2 + 5 = 7 students.