Explanation
Let's say the number of girls is x. Then, the number of boys is 2x (since there are twice as many boys as girls).
Total students = x (girls) + 2x (boys) = 3x
Now, let's calculate the number of students who failed:
Girls who failed = 45% of x = 0.45x
Boys who failed = 30% of 2x = 0.6x
Total students who failed = 0.45x + 0.6x = 1.05x
Now, let's calculate the number of students who passed:
Total students who passed = Total students - Total students who failed
= 3x - 1.05x
= 1.95x
Percentage of students who passed = (1.95x / 3x) × 100%
= 65%