Answer:
18.32 seconds
Explanation:
Given: one washer is 21 ft high rising 8 in per second. The other is 50 feet high descending 11inches per second.
To Find: How long does it take for the two window washers to reach the same height
Solution:
Initial height of first washer


height of first tower

ascending rate of first tower

equation for height of first washer after
seconds

Initial height of second washer


height of second tower

descending rate of second tower

equation for height of second washer after
seconds

when height of both washers are equal




It will take 18.32s to both washers to reach the same height