Answer : The concentration of the
solution is, 2.16 M
Explanation :
To calculate the concentration of base, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is
.
We are given:

Putting values in above equation, we get:

Thus, the concentration of the
solution is, 2.16 M