Rizwan has a box in which he kept red and blue marbles. The red marbles and blue marbles were in the ratio 5 : 4. After he lost 5 red marbles the ratio became 10 : 9. How many marbles does he have now?
In an army selection process, the ratio of selected to unselected candidates was 6:1. If 30 less had applied and 10 less selected, the ratio of selected to unselected would have been 7:1. How many candidates had applied for the process?