#GMAT

[@sachinsavailable]

Bhaskar sir, Thank you for posting outstanding videos. I Appreciate it sincerely and I am sure other too. Regards

[@Wizako]

Sachin. Thanks for your feedback and words of appreciation.

[@bahaarrao4616]

I have a doubt in the class example. The question days that the average of class A and B is 16 years and that of class A is 20 years. So in this case (a) I.e. average of class B comes out to be 4 years and sum of students of class be to be 160 rather that 560. Why is my approach incorrect ?

[@Rocloka]

We know that 20*20 = 400 which is the sum of A. We also know that the average of A and B is 16. This means that (sum of A + sum of B)/(quant of A + quant of B)=16. We have the values for all but the sum of B. (400+B)/(20+40)=16 => (400+B)/60=16 => 400+B=60*16 => B=60*16-400=560. 560/40=14 which is the answer to the question of the average age of class B.

[@ashishsinha9035]

Nice

[@Wizako]

Thank you! Cheers!