Two wires of equal length, one of copper and the other of manganin have the same resistance. Which wire is thicker?

Resistance R of a wire of length l and cross-sectional area A (thickness) is given by, R = ρl/A where ρ = specific resistance of wire
for copper wire R = ρcl/Ac,
for manganin wire R = ρml/Am
or ρc/Ac = ρm/Am
or Ac/Am = ρc/ρm
we know ρm > ρc (as manganin is an alloy)
therefore Ac < Am
Hence manganin wire is thicker.