According to the question,

R = 3 Ohm

l = 10 cm

we get the new length as l’ = 30 cm = 3 × l

R = ρ (l / A)

As a result, new resistance

In the same sequence, stretching length will grow and cross section area will decrease.

R’ = ρ (3l / A / 3)

Therefore

R’ = 9 ρ (l / A)

R’ = 9R

R’ = 9 × 3

R’ = 27 Ohm