The document contains 4 math word problems and their solutions: 1) Choosing 2 students from a group of 4 can be done in 6 combinations. 2) 15 - 3(2+1) = 15 - 3(3) = 15 - 9 = 6 3) A room measuring 8 feet 6 inches by 12 feet with 6-inch tiles needs 408 tiles. 4) A sequence with first terms 3, 5, 7, 9 has a rule of adding 2 to get the next term; a different sequence following the same rule of adding 2 would have first terms 5, 7, 9, 11, and the 100th term would be 198.