Final answer:
To calculate the discharge of a river, you need to use the formula Q = A * V. However, since the dimensions of the river are not given, we cannot calculate the discharge in this case.
Step-by-step explanation:
To calculate the discharge of a river, you need to use the formula Q = A * V, where Q is the discharge, A is the cross-sectional area of the river, and V is the velocity of the river. In this case, since we are given the velocity of the river at the gauge station (6 ft/sec), we need to find the cross-sectional area. Unfortunately, the question does not provide us with the dimensions of the river, so we cannot calculate the discharge.