the average marks of a class of 25 students is 50 and that of another class of 40 students is 65 . find the average marks of all the students ?
"sum of the marks for the class of 25 students = 25 * 50 = 1250 sum of the marks for the class of 40 students = 40 * 65 = 2600 sum of the marks for the class of 65 students = 1250 + 2600 = 3850 average marks of all the students = 4850 / 65 = 59 . answer : d"
divide(add(multiply(25, 50), multiply(40, 65)), add(25, 40))