When both jaws of vernier callipers touch each other, zero mark of the vernier scale is right to zero mark of main scale, \( 4^{\text{th}} \) mark on vernier scale coincides with certain mark on the main scale. While measuring the length of a cylinder, observer observes \( 15 \) divisions on main scale and \( 5^{\text{th}} \) division of vernier scale coincides with a main scale division. Measured length of cylinder is ________ \( \text{mm} \). (Least count of Vernier calliper = \( 0.1 \, \text{mm} \))