The total marks he scored in Test 1 was (type in 0 if it cannot be determined) ___
Subject/TestPhysicsChemistryMathsBiologyTotalTest 11611201966–––Test 21419231773Test 31220291475Test 41118301574Test 51022241672Total639012681360
The average marks scored by Ajay in certain number of tests is 84. He scored 100 marks in his last test. If his average score of all these tests is 86, then the total number of tests he appeared is ____.