Let the length of the pipe be \( h \) cm. - Outer surface area of the pipe = \( 2\pi \times 5 \times h = 10\pi h \) square cm - Inner surface area of the pipe = \( 2\pi \times 4 \times h = 8\pi h \) square cm - Area of the two circular rings (ends) = \( 2\pi(5^2 - 4^2) = 18\pi \) square cm According to the question: \[ 10\pi h + 8\pi h + 18\pi = 1188 \] \[ \pi(18h + 18) = 1188 \] \[ \frac{22}{7} \times (18h + 18) = 1188 \] \[ 18h + 18 = 1188 \times \frac{7}{22} \] \[ 18h = 378 - 18 = 360 \] \[ h = \frac{360}{18} = 20 \] ∴ The length of the pipe is 20 cm.