When both jaws of vernier callipers touch each other, zero mark of the vernier scale is right to zero mark of main scale, 4^th mark on vernier scale…

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