he 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?	Pick:
A) 52.2	B) 59.5	C) 52.8	D) 52.5	E) 52.1
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   Average marks of all the students= 4200/80= 
<gadget id="calculator">4200/80</gadget>
<output>105/2 = around 52.5</output>
52.5   Answer:52.5
<result>D</result>
he 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?