2024 CO CDL Practice Test: Class A - Test 3 Based on 2024 CO CDL Handbook 21. How much tread should be in every major groove of a tire that is not in front? A 1/32 B 2/32 C 4/32 Next More 21/29 Progress 0 Errors Restart Next Next Class A - Test 3 Back to Test List Class A - Test 2 Class A - Test 4 Challenge Library 12 More CO CDL Practice Tests 4 Class A - Test 4 5 Class A - Test 5 6 Class A - Test 6 7 Class A - Test 7 8 Class A - Test 8 9 Class B - Test 10 Class B - Test 2 11 Class B - Test 3 12 Class B - Test 4 13 Class B - Test 5