The average marks of a class of 35 students is 45 and that of another class of 55 students is 65. Find the average marks of all the students? Choose the correct choice from the following: A) 52.6 B) 52.4 C) 52.1 D) 57 E) 52.9
Sum of the marks for the class of 35 students = 35 * 45= 
<gadget id="calculator">35 * 45</gadget>
<output>1_575</output>
1575   Sum of the marks for the class of 55 students= 55 * 65= 
<gadget id="calculator">55 * 65</gadget>
<output>3_575</output>
3575   Sum of the marks for the class of 90 students=   1575 + 3575= 
<gadget id="calculator">1575 + 3575</gadget>
<output>5_150</output>
5150   Average marks of all the students= 5150/90 = 57.Answer: 57
<result>D</result>
The average marks of a class of 35 students is 45 and that of another class of 55 students is 65. Find the average marks of all the students?