Unit Digit Shortcut
Suppose you have a series
P, Q, R, S ,T, P, Q, R, S ,T,P, Q, R, S ,T,P, Q, R, S ,T,P, Q, R, S , T,P, Q, R, S, T …..
And you have to find out the 16 th term of the series. How would you do this?
One way to solve this is by counting the 16 th term; you get your answer P.
The other way to solve : You can divide the 16 by 5 and get the remainder as 1. So now answer would be the 1 st term that is P.
Why we have divided by 5 because the terms in the series are repeated after a cycle of 5.
Let us take another question.
Find out the 25 th term of the above series. Following the same procedure you get
25/ 5 gives you the remainder zero (0)
In such case, your answer should be the last term of the cycle and the last term of the cycle is T
25th term is T.