Answer: 686.
- A 640
- B 686
- C 714
- D 648
Correct answer: B. 686
Explanation: Among 1–999: divisible by 5 is 199, by 7 is 142, by 35 is 28. By 5 or 7 = 313, so neither = 999 − 313 = 686.
Counting tree for selecting 2 items from {A, B, C} without repetition: 3 x 2 = 6 ordered arrangements.
Concept context
Counting, arrangements, and selections