HELP DC CIRCUITS question RESISTIVITY

It's just this last bit of a question - i think the markscheme is wrong but I need to make sure.

It is question 9B:

http://pmt.physicsandmathstutor.com/download/Physics/A-level/Topic-Qs/OCR-A/4-Electrons-Waves-Photons/4.1-4.3-Electricity/Set-A/DC%20Circuits.pdf

Basically the markscheme uses 3.5*10^-5 for the resistivity when the question said the "resistivity of the resistive material = 5.0*10^-6 ohmmeters."

Link to markscheme:
http://pmt.physicsandmathstutor.com/download/Physics/A-level/Topic-Qs/OCR-A/4-Electrons-Waves-Photons/4.1-4.3-Electricity/Set-A/DC%20Circuits%20MS.pdf

Is this incorrect? The answer they got is 0.6mm where i get 1mm.
Could someone tell me what they get? many thanks.

Yes. Looks like an error in the mark scheme.

$R = \frac{\rho L}{wt}$

$t = \frac{\rho L}{wR}$

$t = \frac{5 \mathrm {x}10^{-5}\ \mathrm {x}\ 0.8}{2.5 \mathrm {x}10^{-3}\ \mathrm {x}\ 16}$

$t = \frac{4 \mathrm {x}10^{-5}}{0.04}$

$t = 1 \mathrm {x}10^{-3} \mathrm {m} = 1 \mathrm {mm}$