Does this actually help?

Increasing the number of processors by a factor of 9 will not necessarily increase the processing speed by a factor of 9 too.

The actual benefit of multiple processors depends on factors such as how the much the program benefits from parallel computing (or even makes use of it at all), and how effectively the different processors are able to communicate information between each other. It will also take some amount of time for tasks to be split between the different processors.

These factors (and more) are unknown, so there is $\color{#20A900}{\boxed{\textnormal{insufficient information}}}$ to find how long the task would take on Chris' computer.

Further information:

Using Amdahl's law , we can work out an example. Let us say that 40% of the Agnishom's program's execution time benefits from parallel processing, and that this part is sped up to 5 times faster on Chris' computer.

Chris therefore runs the program $\dfrac{1}{1-0.4+\dfrac{0.4}{5}}=1.47\textnormal{ (3 s.f.)}$ times faster, so in $\dfrac{78498}{1.470588...}=\color{#3D99F6}{\boxed{53379}}$ time units (to the nearest unit).