Free cash flow

Dillin Inc. reported the following on the company's statement of cash flows in $20$ Y $2$ and $20$Y$1$:

Of the net cash flows used for investing activities, $75\%$ was used for the purchase of property, plant, and equipment.

a$.$ Determine Dillin's free cash flow for both years.

b$.$ Has Dillin's free cash flow improved or declined from $20$ Y $1$ to $20$ Y $2?$