Master Wang processed a batch of parts, 9 / 16 of which were processed in 3 hours, exactly 18 (1) 18 △ 3 means [] (2) 9 / 16 △ 3 means [] (3) 9 / 16 of 18 means [] (4) 9 / 16 of 3 means []

Master Wang processed a batch of parts, 9 / 16 of which were processed in 3 hours, exactly 18 (1) 18 △ 3 means [] (2) 9 / 16 △ 3 means [] (3) 9 / 16 of 18 means [] (4) 9 / 16 of 3 means []

Number of parts processed per hour Percentage of parts processed per hour Total number of parts At this speed, it takes time to finish processing

Write the meaning of the formula according to the condition
To build a 200 meter long road, one fifth of the total length was built on the first day, and one fourth of the total length was built on the second day
(1) 200 * 1 / 5————————————————————
(2) 200 * 1 / 4————————————————————
(3) 200 * (1 / 4 + 1 / 5) is:-
(4) 200 * (1 / 4-1 / 5)-
(5) 200 * (1-1 / 4-1 / 5)-
(6) 1 / 4 / 1 / 5 is: ---————
(7) 1 / 5 of 1 / 4 of 1 is: ---————

Length of first day repair
The length of the second day's repair
The total length of the first day and the second day
The second day is longer than the first
There is still a length left to be repaired
The second day was a fraction of the first
The first day was a fraction of the second