A school has only the classes having 20, 30 and 40 students respectively. The percentages of students passed are 30%, 50% and 60% respectively. The percentage of passed students in the entire school is-

প্রশ্নঃ A school has only the classes having 20, 30 and 40 students respectively. The percentages of students passed are 30%, 50% and 60% respectively. The percentage of passed students in the entire school is-