A can complete a work in 20 days and B can complete the same work in 25 days. If both of them work together, then in 3 days what percent of the total work will be completed?
The mean of marks secured by 30 students in division-A of class X is 67, 55 students of division-B is 63 and that of 40 students of division-C is 61. What is the mean of marks of the students of three divisions of Class X?
In the following figure, square represents Pharmasists, triangle represents Singers, circle represents Surgeons and rectangle represents Mothers. Which set of letters represents Surgeons who are either mothers or singers?