The average marks of a class of 30 students is 40 and that of another class of 50 students is 60. Find the average marks of all the students?	Select
A) 52.5	B) 52.9	C) 52.1	D) 52.3	E) 42.5
Sum of the marks for the class of 30 students = 30 * 40= 
<gadget id="calculator">30 * 40</gadget>
<output>1_200</output>
1200   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 80 students=   1200 + 3000= 
<gadget id="calculator">1200 + 3000</gadget>
<output>4_200</output>
4200   52.5verage marks of all the students= 4200/80= 
<gadget id="calculator">4200/80</gadget>
<output>105/2 = around 52.5</output>
52.5   52.5nswer:52.5
<result>A</result>
The average marks of a class of 30 students is 40 and that of another class of 50 students is 60. Find the average marks of all the students?