A bridge is built across the river. The river is 120 metres wide. One quarter of the bridge is over the left river bank and one quarter of the bridge is over the right river bank. How long is the bridge?

Explanation

The river is 120 metres wide. If one quarter of the bridge is over the left bank and another quarter is over the right bank, this means half the bridge spans the river, while one quarter of the total length extends on each side. Therefore, the bridge length is twice the width of the river: 120 metres divided by the half that spans the river equals 240 metres in total length. This explains why Option D is correct. Options A, B, and C are incorrect as they do not account for the full length needed when adding the quarters on each side of the river.