17/25× 1 1+ 1 1/25× 18= 1 1/25*( 17+ 18)= 1 1*35/25=77/5

A has to climb four flights of stairs to go up to the fifth floor, and B has to climb two flights of stairs, so it takes half as long as A, so (5/ 1 1)

The first cut was 6 meters, and the second cut was 0.25 meters, so it was 6.25 meters, which means it was shortened by 6.25 meters, leaving 24-6.25= 17.75 meters.