A certain group of students is traveling by train. 30 students have mobile phones and 20 students have tablets. 15 students have a mobile phone as well as a tablet, while another 15 students have neither a mobile phone nor a tablet. What is the total number of students traveling?

Among 100 people, 40 people like tea, 58 people like coffee, and 26 people like both tea and coffee. Find the number of persons who like neither tea nor coffee.

In an examination of 500 candidates comprising tests in English, Hindi, and Mathematics, the failure counts in individual and combined subjects are given as follows: - Failed in English and Hindi only = 9 - Failed in English and Mathematics only = 12 - Failed in Hindi and Mathematics only = 13 - Failed in all three subjects = 5 What is the percentage of candidates who failed in at least two subjects?