the average marks of a class of 22 students is 40 and that of another class of 28 students is 60 . find the average marks of all the students ?
"sum of the marks for the class of 22 students = 22 * 40 = 880 sum of the marks for the class of 28 students = 28 * 60 = 1680 sum of the marks for the class of 50 students = 880 + 1680 = 2560 average marks of all the students = 2560 / 50 = 51.2 answer : a"
divide(add(multiply(22, 40), multiply(28, 60)), add(22, 28))