Thread: average

class A contains 54 students and the average mark of the class is 70 and class B contains 41 students and average mark of this class is 73 and class C contains 32 students and the average mark of this class is 76 so whats the average of all the three classes

options
below 70
above 70 below 73
between 73 and 76

i actually solved it has (54*70+41*73+76*32)/54+2+41 so i marked it has below 70 but the answer was between 73 and 76 ..how is it possible can any one explain

Originally Posted by bluffmaster.roy.007

class A contains 54 students and the average mark of the class is 70 and class B contains 41 students and average mark of this class is 73 and class C contains 32 students and the average mark of this class is 76 so whats the average of all the three classes

options
below 70
above 70 below 73
between 73 and 76

i actually solved it has (54*70+41*73+76*32)/54+2+41 so i marked it has below 70 but the answer was between 73 and 76 ..how is it possible can any one explain

The correct calculation is (54*70+41*73+76*32)/(54+32+41). Unless you're making data entry errors on your calculator, you will get 72.48.