5 votes 5 votes The arithmetic mean of attendance of $49$ students of class $\text{A}$ is $40%$ and that of $53$ students of class $\text{B}$ is $35%.$ Then the percentage of arithmetic mean of attendance of class $\text{A}$ and $\text{B}$ is $27.2\%$ $50.25\%$ $51.13\%$ $37.4\%$ Probability isro2011 probability arithmetic-mean + – go_editor asked Jun 23, 2016 • retagged Dec 8, 2022 by Lakshman Bhaiya go_editor 3.5k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 13 votes 13 votes AM of attendance of 49 students of class A = 40% AM of attendance of 53 students of class B = 35% AM of attendance of class A and B= $\frac{49*40+35*53}{( 49+53)}$= $\frac{3815}{ 102}$ = 37.4019% Hence,Option(D)37.4% is the correct choice. LeenSharma answered Jun 23, 2016 • selected Jun 23, 2016 by Arjun LeenSharma comment Share Follow See all 0 reply Please log in or register to add a comment.
1 votes 1 votes 40% of 49 students are 49⨉40/100 =19.6=20 35% of 53 students are 53⨉35/100 =19 Among 102 students present 39 students " 1 " " 39/102 " " 100 " " 39/102⨉100 =38 Ans D) srestha answered Jun 23, 2016 srestha comment Share Follow See all 3 Comments See all 3 3 Comments reply Arjun commented Jul 2, 2016 reply Follow Share This is wrong :( 0 votes 0 votes srestha commented Jul 2, 2016 reply Follow Share No @Sir it is not wrong I think. It needs more accurate value :) 1 votes 1 votes Arjun commented Jul 2, 2016 reply Follow Share yes, (y) 0 votes 0 votes Please log in or register to add a comment.
–1 votes –1 votes AM OF A=40% AM OF B=35% by doing mean of these two class also we can get the answer =(a+b)/2 =(40%+35%)/2 = 37.5% option d is correct sravanghanta answered Jul 2, 2016 • edited Jul 2, 2016 by sravanghanta sravanghanta comment Share Follow See 1 comment See all 1 1 comment reply ARDHAKAD commented Jun 18, 2022 reply Follow Share If we have M Things with an average of P and N Things with an average of Q , now whatever is the value of M and N , when both groups are merged ,the average will always be somewhere between P and Q . ( I am expecting that we don’t have negative no. of things , like -3 peoples with average height 160 cm .) In this particular question we have only one option in that range so if we know this fact we don’t need to calculate . 0 votes 0 votes Please log in or register to add a comment.