To find out how many candidates appeared in the examination

Question

In a examination, 30 %of the candidates failed in English, 35 %failed in GK and 27 %failed in both the subjects. If 310 candidates passed in both the subjects,how mama candidates appeared in the examination? 

Answer 1

Drawing a Venn diagram might help.

 

27% failed both. 30% failed English, but 27% of those 30% failed both. So 3% failed only English.

 

Also, since 35% failed GK, but 27% of those failed both, 8% failed only GK

 

The total number that failed at least one subject is 27+3+8 = 38%

 

This means 62% passed.

 

Now use that 62%, which are 310 people, to find how many people took the test