The red scarf hydrological station of the school measured the depth of the river. Pulled out a pole from the river. (2/15) of the pole was inserted into the mud, and (1/10) was exposed to the water surface. When the water surface rose by 12 cm, the water depth was exactly (5) of the pole /6), what is the original depth of the river in centimeters?
学校红领巾水文站测量河水深度，把一根标杆拔出河中，标杆的(2/15)插在泥中，(1/10)显露水面，当水面上升12厘米时，水深正好占标杆的(5/6)，河水原来的深度是多少厘米？
<gadget id="calculator">23 / 30</gadget>
<output>23/30 = around 0.766667</output>

<gadget id="calculator">12 * (23/30)</gadget>
<output>46/5 = around 9.2</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(5/6) - (23/30)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(46/5) / (1/15)</gadget>
<output>138</output>

<result>138</result>