In an examination,the ratio of the number of candidates who passed, to those who failed was 5 : 2. If the number of failed candidates had been 14 more, then the ratio of the number of passed candidates to those who failed would have been 4 : 3. How many candidates passed in examination?

Given, 

the ratio of the number of candidates who passed, to those who failed was 5 : 2

Let the candidates who passed = 5x and who failed = 2x

Condition given in the question is : 

• If the number of failed candidates had been 14 more, then the ratio of the number of passed candidates to those who failed would have been 4 : 3

so, $$\frac{5x-14}{2x+14}=\frac{4}{3}$$

$$\therefore\ 15x-42=\ 8x+56$$

$$\therefore\ x=14$$

Number of candidates passed is 5x.

i.e; $$5\times\ 14=70$$

Hence, Option B is correct.