Predict state of a Counter using RS flip flops

Question

 A three stage counter is made up of RS Flip flops and initial value is 1. What will be the value after 5 clock pulses?

( how to easily solve these type of questions? Please explain)

Answer 1

Initial value is 1

So after 1st clock pulse value becomes 2

After 2nd clock pulse value becomes 3

After nth clock pulse value becomes (n+1) mod 7= 6 mod 7=6