Given decimal is 0.181818......
Let us assume,
x=0.181818........ ---(1)
Multiply both sides of (1) by 100
∴ 100x = 18.1818.... ---(2)
Subtracting (1) from (2), we get 100x−x=18.1818....− 0.1818......
⇒99 x=18 ⇒ x=1899 =211
∴pq form of the given decimal is 211.
p+q = 2+11 = 13