Solution: Take everyone's workload as the unit 1.
It is also necessary to increase/kloc-0 /× 25× 20/(/kloc-0 /× 20)-20 = 25-20 = 5 people.
15. For a project, Party A will do it for 3 days first, and then Party B will join in. Two-thirds of the projects completed after 4 days are 1 and three-quarters of the projects completed after 10. A was transferred because of some things, and B did the rest. How many days did a * * * do?
Solution: according to the meaning of the problem
The cooperation between Party A and Party B began in 4 days13 and ended in 3/4 days 10.
So the cooperation between Party A and Party B is10-4 = 3/4- 1/3=5/ 12 in 6 days.
Therefore, the work efficiency of both parties is =(5/ 12)/6=5/72.
Then the working efficiency a = (1/3-5/72× 4)/3 = (1/3-5/18)/3 =1/54.
Party B's work efficiency = 5/72-1/54 =11/216.
Then B needs to complete the remaining (1-3/4)/(11/216) = 54/11day.
A * * * made 3+10+54/1=17 and10//day.
16, both parties made the same parts. /kloc-After 0/6 days, Party A needs 64 B and 384 B to complete it. The work efficiency of Party B is 40% less than that of Party A, so how can we find the efficiency of Party A?
Solution: Let the working efficiency of A be A/ day, and then B be (1-40%)A = 0.6a/ day.
According to the meaning of the question
16a+64=0.6a× 16+384
16×0.4a=320
0.4a=20
A=50/day
A's work efficiency is 50/ day.
Arithmetic method:
B does 40% less than A every day.
Then 16 days is 384-64= 320 less.
Do 320/ 16 = 20 less every day.
Then the working efficiency of A = 20/40% = 50/ day.
17, Master Zhang has a rest every six days 1 day, and Master Wang has a rest every five days for two days. For an existing project, Master Zhang needs 97 days and 75 days. If two people cooperate, how many days does a project take?
Solution:
97 divided by 7 equals 13, leaving 6 13 * 6 = 78, 78+6 = 84 working days.
75 divided by 7 equals 10,5,10 * 5 = 50,50+5 = 55 working days.
Master Zhang completes 1/84 every working day and 6/84 =114 every week.
Master Wang completes 1/55 every working day and 5/55 =11/every week.
Two people work together to complete 139/4620 every working day and 25/ 154 every week.
Six weeks to complete 150/ 154, leaving 4/ 154.
(4/ 154)/( 139/4620)= 120/ 139
So, six weeks and one day, 43 days.
18, Party A, Party B and Party C jointly complete a project, and complete it all in three days15. Then Party A rested for three days, Party B rested for two days, and Party C didn't rest. If Party A's workload is three times that of Party C and Party B's workload is four times that of Party C, how many days will it take to complete the work from scratch?
Solution: The sum of the working efficiencies of A, B and C = (1/5)/3 =115.
Work efficiency c = (115)/(3+4+1) =1120.
A's work efficiency =1120× 3 =1/40.
Party B's work efficiency =1120× 4 =1/30.
Here, the working efficiency of C is regarded as a multiple of 1.
A rest for 3 days, B rest for 2 days, and a * * * is finished.
1/30+ 1/ 120×3=7/ 120
Then the remaining needs (1-1/5-7/120)/(115) = 89/8 days.
A * * * takes 3+3+89/8= 17 and 1/8 days.
19. Party A works alone for 30 days and Party B works alone for 20 days. After Party A works alone for a few days, Party B takes over, Party A works alone for 22 days, and Party A works alone for several days.
Solution: work efficiency B = 1/20.
B Completed in 22 days1/20× 22 =1110.
Complete1110-1=1/kloc-0.
The work efficiency difference between Party B and Party A =1/20-1/30 =1/60.
So A did (110)/(1/60) = 6 days.
B did it for 22-6= 12 days.
Considering that chickens and rabbits are in a cage.