Aboat has a speed of 15 mph in still water. it travels downstream from greentown to glenavon in g hours. it then goes back upstream from glenavon to cambria, which is 2 miles downstream from greentown, in g hours. find the rate of the current.

Answer

rate of current = (1/x) mph

Explanation
let the distance from Greentown to Glenavon be y miles and the rate of current be x mph.

y = (15+x)g
y = 15g+gx (1)

The distance from Glenavon to Cambria = (y-2)

y-2 =(15-x)g
y-2 = 15g-gx
y = 15g - gx + 2 (2)

equation equation (1) and (2)

15g + gx = 15g - gx + 2
2gx = 2

dividing by 2g both sides we get,

x = 1/2g mph