(1)
(a)
the resistance is given as
R = ρl/A
where
ρ = resistivity
l = length of the resistor
A = area of cross-section
now, if the resistor is cut into four equal parts, let the length of each part will be l' = l/4
so, the each new resistance will be
R' = ρl'/A = ρl / 4A = (1/4).(ρl/A) = R/4
thus, the resistance of each resistor will reduce to quarter its original value.