The average marks of a class of 28 students is 40 and that of another class of 50 students is 60. Find the average marks of all the students?  Choose the correct choice from the following
A) 52.2	B) 59.5	C) 52.8	D) 52.5	E) 52.1
Sum of the marks for the class of 28 students = 28 * 40= 
<gadget id="calculator">28 * 40</gadget>
<output>1_120</output>
1120   Sum of the marks for the class of 50 students= 50 * 60= 
<gadget id="calculator">50 * 60</gadget>
<output>3_000</output>
3000   Sum of the marks for the class of 78 students=   1120 + 3000= 
<gadget id="calculator">1120 + 3000</gadget>
<output>4_120</output>
4120   Average marks of all the students= 4120/78   = 52.8   Answer:52.8
<result>C</result>
The average marks of a class of 28 students is 40 and that of another class of 50 students is 60. Find the average marks of all the students?