Bob, please confirm if I got this right and if not, please help to solve

Question

1)A wire has a resistance of 10 ohm at 20 deg celsius and 13.1 ohm at 100 deg celsius. Obtain a value for its temperature coefficient of resistance.
ans I got is this=
using Rt = Ro (1 + alpha(T-To))
13.1=10(1 + alpha(100-20))
13.1 = 10(1+80 alpha)
alpha = 3.1/800 = 0.003875

I didn't do the calc, but you did the right algebra.

... and don't foget the units.