The given series ⇒ 5a, 10B, 15c, 20D
Each term consists of a number and letter.
It may be divided into (5 , 10 , 15 , 20 , ......) and ( a , B , c , D , ........)
The series of numbers is arithmetic series.
The first term (a) is 5 and the common difference (d) is 5
It has a general equation = a + (n-1)d
So, next step in the series is the fifth term = a + (5-1)d = 5 +(5-1) ×5 = 25 ⇒⇒ (1)
The series of letters is the sequence of letters from a to z but with the sequence is ( capital , small , capital , ....)
So, next step in the series will be the letter after D in small case
Which is = e ⇒⇒(2)
From (1) and (2)
∴ The next step in the series ( 5a, 10B, 15c, 20D) is ⇒⇒⇒ 25e
