Aschool bus has 25 seats, with 5 rows of 5 seats. 15 students from the first grade and 5 students from the second grade travel in the bus. how many ways can the students be seated if all the first-grade students occupy the first 3 rows? a. 25p20 b. 5p5 × 20p15 c. 15c15 × 10c5 d. 15p15 × 10p5 e. 15p15 × 10c5

Question 2(multiple choice worth 1 points) simplify 7 square root of 3 end root minus 4 square root of 6 end root plus square root of 48 end root minus square root of 54. 11 square root of 6 end root minus 7 square root of 12 11 square root of 3 end root minus 7 square root of 6 negative 3 square root of 9 4 square root of 9