In an examination 70% of the candidate passed in English, 80% passed in Mathematics, 10% failed in both subjects. If 144 candidates passed in both, the total number of candidates was :

Failed candidates in English = (100 - 70) = 30%
Failed candidates in Mathematics = (100 - 80) = 20%
Candidates who fail in both subject = 10% Candidates who only fail in English = 30 - 10 = 20%
Candidates who only fail in Mathematics = 20 - 10 = 10%
Percentage of passed students in both subject
= 100 - (Candidates who only fail in English + Candidates who only fail in Mathematics + Candidates who fail in both subject)
= 100 - (20 + 10 + 10)
= 60%
According to the question,
60% of students = 144
Total students :
= $$\frac{144}{60}$$ × 100
= 240