Verified answer

= (3/5 π t) (1/3 π)

since everything is multiplied, you can separate everything with parentheses and rearrange them around.

= (3/5) (1/3) (π) (π) (t)

= (3/15) (π²) (t)

= (1/5) (π²) (t)

= π²t/5

I am assuming you are just simplifying or manipulating the equation. If you need it in other ways.. let us know.

(3/5 π t) (1/3 π)

(3/5t π) (1/3 π)

3/15t π^2

t/5 π^2