1. Look at this series: F2, __, D8, C16, B32, ... What number should fill the blank?
Answer and Solution : E4 The letters decrease by 1; the numbers are multiplied by 2. 2. Look at this series: 664, 332, 340, 170, ____, 89, ... What number should fill the blank?
Answer and Solution :178This is an alternating division and addition series: First, divide by 2, and then add 8.
3. Look at this series: V, VIII, XI, XIV, __, XX, ... What number should fill the blank?
Answer and Solution :XVIIThis is a simple addition series; each number is 3 more than the previous number. 4. Look at this series: 70, 71, 76, __, 81, 86, 70, 91, ... What number should fill the blank?
Answer and Solution :70In this series, 5 is added to the previous number; the number 70 is inserted as every third number. 5. Look at this series: 8, 43, 11, 41, __, 39, 17, ... What number should fill in the blank?
Answer and Solution :14This is a simple alternating addition and subtraction series. The first
series begins with 8 and adds 3; the second begins with 43 and
subtracts 2.
The letters decrease by 1; the numbers are multiplied by 2.