The average marks of a class of 25 students is 40 and that of another class of 30 students is 60. Find the average marks of all the students?
Choose the most appropriate option:
A) 52.6
B) 52.4
C) 52.1
D) 50.9
E) 52.9
Sum of the marks for the class of 25 students = 25 * 40= 
<gadget id="calculator">25 * 40</gadget>
<output>1_000</output>
1000   Sum of the marks for the class of 30 students= 30 * 60= 
<gadget id="calculator">30 * 60</gadget>
<output>1_800</output>
1800   Sum of the marks for the class of 55 students=   1000 + 1800= 
<gadget id="calculator">1000 + 1800</gadget>
<output>2_800</output>
2800   Average marks of all the students= 2800/55 = 50.9.Answer: 50.9
<result>D</result>
The average marks of a class of 25 students is 40 and that of another class of 30 students is 60. Find the average marks of all the students?