Two patterns in one sequence
Read positions 1, 3, 5 and 7 as one number pattern. Read positions 2, 4, 6 and 8 as another. Each pattern adds or subtracts the same amount each time. Find the missing number.
Read positions 1, 3, 5 and 7 as one number pattern. Read positions 2, 4, 6 and 8 as another. Each pattern adds or subtracts the same amount each time. Find the missing number.