help me find the speed of this questions

Question

When Eugene rows his gondola in still water he travels at 3 mph.
When Eugene rows his gondola in the Grand Canal, he
can travel 2.8 miles when rowing with the current in the same
amount of time as he can travel 2 miles when rowing against
the current.

Find the speed of the current

Answer 1

speed=distance*time

speed/distance=time

 

speed1 = speed_with_current=rowing_speed+current_speed

speed2 = speed_against_current=rowing_speed-current_speed

where rowing_speed=3 and current_speed is your unknown value

 

distance1=2.8

distance2=2

speed1/distance1=time=speed2/distance2

(rowing_speed+current_speed)/distance1=(rowing_speed-current_speed)/distance2

(3+current_speed)/2.8=(3-current_speed)/2

solve for current_speed (to make things easier to see let's substitute x for current_speed)

(3+x)/2.8=(3-x)/2

2(3+x)=2.8(3-x)

6+2x = 8.4-2.8x

4.8x=2.4

x=0.5

 

current speed = 0.5mph