The given sequence is with the same common difference between the two consecutive number in the series thus it is said to be the Arithmetic progression ( AP).
For finding the nth term in the AP we have a formula tn = a + (n-1) × d
Here a is the first term , n is the number of the term to be founded and d is the common difference between the two consecutive number in the series.
Thus here tn = 5 + ( 22 - 1 ) × 3.
On subtracting we get tn = 5 + (21 ) × 3
On multiplying we get tn = 5 + 63
After adding we get tn = 68. It is the 22nd term in the given series.
Every time the number is divided by 2 like 8 divided by 2 is 4 and 4 divided by 2 is 2 and so on so if you divide 1/4 by 2 it would be 0.125 and that in fraction would be 1/8.