Question - Look at this series: 80, 10, 70, 15, 60, ... What number should come next?
A. 20
B. 25
C. 30
D. 50
Answer -
A) 20
Explanation:
This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.