Saved Bookmarks
| 1. |
Theaverage marks of boys in a class is 52 and that of girls is 42. The averagemarks of boys and girls combined is 50. The percentage of boys in the classis(1)40 (2) 20(3) 80 (4) 60 |
|
Answer» `B:G=x:y` `Mavg=(Mb.x+My.y)/(x+y)` `50=(52x+42y)/(x+y)` `50x+50y=52x+42y` `2x=8y` `x/y=4` `%b=x/(x+y)xx100` `=x/(5x/4)xx100` `=100xx4/5` `=80%` option`(c)=80` |
|