Xiaogang and his father measured the length of a bridge on foot. They started from both ends of the bridge and walked toward each other. When they met, Dad walked 115 steps and Xiao Gang walked 109 steps. If Dad's average stride length is 7 decimeters and Xiaogang's average stride length is 5 decimeters, what is the length of the bridge?
小刚和爸爸步测一座桥的长度，他们分别从桥的两端出发，相向而行．相遇时爸爸走了115步，小刚走了109步．如果爸爸的平均步长是7分米，小刚的平均步长是5分米，这座桥的长是多少米？
<gadget id="calculator">805 + 545</gadget>
<output>1_350</output>

<gadget id="calculator">1_350 / 10</gadget>
<output>135</output>

<result>135</result>