This document contains 7 math problems involving combinations and permutations: 1) Number of arrangements of 4 pictures from 9 is 9C4. 2) Number of ways to select 3 officers from 12 club members is 12C3. 3) Number of outfits from given clothing items is (8t-shirts)*(2 belts)*(5 jeans)*(3 shoes). 4) Number of arrangements of 7 people in a group picture is 7!. 5) Evaluates to 7*6*5 = 210. 6) Evaluates to 70. 7) Evaluates to 39916800.