Answer
See explanation.
Work Step by Step
The positions of the nodal and antinodal lines depend on the wavelength, not the amplitude, so they are unaffected.
On the antinodal lines, the 2 waves will totally reinforce each other as before. If the 2 amplitudes are A and 2A, the new amplitude will be 3A and the relative intensity will be 9I.
On the nodal lines, the 2 waves cannot totally cancel because they are not of equal amplitude. They will partially cancel. If the 2 amplitudes are A and 2A, the new amplitude will be A and the relative intensity will be I.