15
8
1
3
Answer is Wrong!
Answer is Right!
The answer is 1.
The missing number is the number that, when added to the other two numbers, gives a multiple of 3. In this case, 1 + 8 = 9, which is a multiple of 3. Therefore, the missing number is 1.
Option A, 15, is not the correct answer because 15 + 8 = 23, which is not a multiple of 3.
Option B, 8, is not the correct answer because 8 + 1 = 9, which is already a multiple of 3.
Option C, 1, is the correct answer because 1 + 8 = 9, which is a multiple of 3.
Option D, 3, is not the correct answer because 3 + 8 = 11, which is not a multiple of 3.