In an army selection process, the ratio of selected to unselected candidates was 4:1. If 90 less had applied and 20 less selected, the ratio of selected to unselected would have been 5:1. How many candidates had applied for the process?

Let $$5x$$ candidates applied for the process.

Candidates selected = $$4x$$ and candidates not selected = $$x$$

If candidates applied = $$5x - 90$$

Candidates selected = $$4x - 20$$

=> Candidates not selected = $$(5x - 90) - (4x - 20) = x - 70$$

According to ques,

=> $$\frac{4x - 20}{x - 70} = \frac{5}{1}$$

=> $$4x - 20 = 5x - 350$$

=> $$x = 350 - 20 = 330$$

$$\therefore$$ Number of candidates who applied for the process = $$5 \times 330 = 1650$$

=> Ans - (A)