Among five friends B, C, D, E and F each studies in a different standard, viz, 2nd, 5th, 8th, 10th and 12th. C studies in a standard which is an even number. D is F’s senior but does not study in 12th standard. Only three students are senior to B. C is senior to B but junior to D. In which standard does F study?
Only three students are senior to B. C is senior to B but junior to D. It means B studies in 5th standard. C studies in a standard which is an even number. C studies either in 8th or 10th standard. D is F’s senior but does not study in 12th standard. D does not study in 12th standard it means D studies in 10th standard. D is F’ senior that means F studies in 2nd standard. E is the one who studies in 12th standard. So, case 2 will get discarded. 
Final arrangement as shown below: 
