If he's not playing games, then the i3 is better. I bet he was looking at some crap synthetic benchmarks like PassMark something else just as bad.
Just taking clockspeed in consideration, the A6 would need to clocked to around 2.8GHz to equal the performance of a core i3. The A6 is a quad core CPU so as long as he is using programs that can take advantage of 3 or more cores, he should get a little better performance than a dual core CPU of the same clockspeed. It is not a linear increase in performance; meaning going from 2 cores to 4 cores will not double performance. The actual performance depends on how well the program has been designed to make use of multiple cores. On average it will probably be around 30% - 40%.
Click the following link to see how a Core i5-3470 (quad core) compares to the Core i3-3220 (dual core). There is only a 100MHz difference in clockspeed. Notice the performance difference is not doubled going from 2 cores to 4 cores. Note that in some benchmarks higher is better, in others lower is better.
http/www.anandtech.com/bench/Product/702?vs=677
The link below compares the A6-3650 vs. the Core i3-3220. Both are desktop CPUs, but since the laptop version CPUs have the same architecture as the desktop CPUs a performance comparison is possible. Again, in some benchmarks higher is better, in others lower is better.
http/www.anandtech.com/bench/Product/403?vs=677
The dual core i3-3220 basically outperforms the quad core A6-3650 in all the benchmarks. In a few of them by a pretty large margin.