The terms in the given alpha-numeric series follow a certain pattern. However, some terms are missing. Choose the correct sequence of the missing terms from the options given below:
Z_25YB23XC_W_19_E17
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A, 21, D, V
The series is made of three-part groups: a letter, a letter and a number. Writing the known terms in groups shows a separate rule for each part:
Groups: Z _ 25 | Y B 23 | X C _ | W _ 19 | _ E 17
First letters Z, Y, X, W, ?:
One step back each time
So the last group starts with V
Second letters ?, B, C, ?, E:
One step forward
So the missing ones are A (before B) and D (after C)
Numbers 25, 23, ?, 19, 17:
2 less each time
So the missing number is 21
Complete series: ZA25 YB23 XC21 WD19 VE17