Answer:
speed of the boat = 100 mph
Explanation:
Let x = speed of the boat
upstream speed = x - 4
downstream speed = x + 4
time = 24/(x - 4) = 26/(x + 4)
Cross multiply:
24(x + 4) = 26(x - 4)
24x + 96 = 26x - 104
104 + 96 = 26x - 24x
200 = 2x
x = 100 mph