The average marks of a class of 20 students is 40 and that of another class of 50 students is 60. Find the average marks of all the students? Pick:
A) 44.28  B) 54.28  C) 34.28  D) 64.28  E) 74.28
Sum of the marks for the class of 20 students = 20 * 40= 
<gadget id="calculator">20 * 40</gadget>
<output>800</output>
800   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 70 students=   800 + 3000= 
<gadget id="calculator">800 + 3000</gadget>
<output>3_800</output>
3800   Average marks of all the students= 3800/70 = 54.28   ANSWER:54.28
<result>B</result>
The average marks of a class of 20 students is 40 and that of another class of 50 students is 60. Find the average marks of all the students?