Answer
5.03 minutes.
Work Step by Step
Find $\gamma$ at v = 0.10 c. It is $\frac{1}{\sqrt{1-v^{2}/c^{2}}}$, or $\frac{1}{\sqrt{1-0.10^{2}}}$, which is $\frac{1}{\sqrt{1-0.01}}=1.005$.
The factor $\gamma$ is the time dilation factor. Multiplying 5 minutes by $\gamma$ gives 5.03 min.