Each student in mr. farmers class took 42 tests this school year. mr. farmer has 8 students in his class. which pair of expressions shows two ways to determine the total number of tests mr. farmer graded this year? a) 40 × 2 and 40 × 8 b) 42 × 8 and 40 × 8 c) (42 × 8) + (2 × 8) and 8 + 8 + 8 + 8 + 8 + 8 + 8 + 8 d) (40 × 8) + (2 × 8) and 42 + 42 + 42 + 42 + 42 + 42 + 42 + 42