KA-0023●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedA password is one letter from A, B, C followed by two digits from 1 to 5. Digits may repeat. How many passwords are possible?CNT-03The multiplication principlealso CNT-05
KA-0069●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedIn a class of 30, 18 play football and 14 play chess. 6 play both. How many play neither?CNT-10Inclusion–exclusion with two setsalso CNT-09
KA-0073●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedHow many different four-letter arrangements can be made from the letters of the word MATH, using each letter once?CNT-05Arrangements of a few objectsalso CNT-03
KA-0074●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedTwo students are chosen from a group of six to represent the class. How many different pairs are possible?CNT-06Selections of a few objectsalso CNT-08