Step 1

Introduction of arithmetic modular: - Let 4, B and R be an integers then an arithmetic modular can be defined as (A)mod \(B=R\)

Where, \(A =\) divident

\(B =\) divisor

\(R=\) remainder

Step 2

Given that \((19-8) \mod 7\)

It can be wriiten as

\((19-8) \mod 7 = (11) \mod 7\)

\(\text{Since} \frac{11}{7} =4\)

\(\text{Therefore}, (11)\mod 7 =4\)

Hence,

\((19 - 8)\mod 7 =4\)