The balanced chemical equation for the reaction between HBr and Ba(OH)2 is:
2HBr+Ba(OH)2→BaBr2+2H2O
From this equation, we can see that 2 moles of HBr react with 1 mole of Ba(OH)2.
Equal equivalents will react.
Number of equivalents = Normality ×Volume
So,
N1V1=N2V20.02×V1=0.02×10V1=10ml