2. For a project, Party A needs to do it alone 12 hours. It takes 65,438+08 hours for Party A to do it first, then 65,438+0 hours for Party A to replace Party B, and then 65,438+0 hours for Party A to replace Party B ..... How many hours will it take them to complete the task? A 1 hour B 1 hour * * do:112+18 = 5/36 Seven rounds * * do: 7 * 5/36 = 36. 12)= 1/3 hours, so a * * * will: 7*2+ 1/3= 14 and 1/3 hours to process a batch of parts, which will be completed in 24 days. Now Party A does 16 days, and then. Party A can cooperate for 12 days:12 *1/24 =1/2, then Party A can cooperate for 4 days: 3/5-1/2 =1/kloc-0. 40= 1/60 *** There are: 3/(1/40-1/60) = 360 copies. A project can be completed by Party A alone for 63 days, and then by Party B alone for 28 days. If both parties cooperate, it will take 48 days to complete. Now Party A works alone for 42 days. The cooperation between Party A and Party B is completed in 28 days: 28* 1/48=7/ 12. Then Party A: 63-28=35 days:1-7/12 = 5/12, that is, what Party A does in one day: (5/66 1 12, then B needs: (/kloc-0
3. (1-3/15) ÷1/25 = 20 (days) Take the item as "1".
4.a's speed: 1/6 B's speed:110 Let's play for n hours. B then called1=1/6 * n+(7-n) *110n = 4.5, so A played for 4.5 hours, and the chicken and rabbit were still in the same cage. Type B 3010 = 3 servings per hour. Now, if A's typing time is regarded as the number of "rabbits" and B's typing time as the number of "chickens", then the total is 7. The number of "rabbits" is 5, the number of "chickens" is 3, and the total is 30, so the problem becomes "chickens and rabbits".
5. It takes 16 days to work out the problem B alone, so the parts in this batch are: 420/(1-817-8/16) = 14280 pieces1.
6. Let the efficiency of A be X, B be Y, C be Z, and the total amount QQ=5x+5y=4y+4z=6y+2x+2z, so z=x+y, and because 5x+5y=4y+4z, so x=3y, so z = 4y+2z.