Answer:
Nicholas' speed: 61.9772 miles/hour
current's speed: 6.8864 miles/hour
Explanation:
Let's call Nicholas's speed "x", and the current speed "y".
Going downstream, the total speed is x+y, and we can formulate the equation:
(x+y)*44 = 3030 -> x+y = 68.8636 miles/hour
Going upstream, the total speed is x-y, and we can formulate the equation:
(x-y)*55 = 3030 -> x-y = 55.0909 miles/hour
If we sum both equations, we have that:
2x = 123.9545
x = 61.9772 miles/hour
Now, to know the current speed, we just apply "x" value in one of the equations:
x+y = 68.8636 -> 61.9772 + y = 68.8636 -> y = 6.8864 miles/hour