A and B can do a piece of work in 45 days and 40 days, respectively. They began to do the work together but A left after some days and then B completed the remaining work in 23 days. The number of days after which A left the work, is?

Total man hours work done by men supplied by A, B and C
= (20 x 8 x 6), (15 x 9 x 7), (10 x 6 x 8) and the wages must be in the ratio of the work done.
So, ? 636 has to divided among A, B and C in the ratio (20 x 8 x 6) : (15 x 9 x 7) : (10 x 6 x 8) = 64 : 63 : 32
? C's share = (32/159) x 636 = ? 128

Fraction of work complete by (A and B) + Fraction of work complete by (B and C) + Fraction of work completed by C = 1
As B did the work for 8 days we can say B did the work for 3 days with A and B did the work for 5 days with C. So, A and B together did the work for 3 days, B and C together did the work for 5 days, C alone did the work for 5 days.
? 3/12 + 5/15 + 5/x = 1 or 5/x = 5/12
i.e., x = 12 or C alone can complete the work in 12 days

(A + B)'s one day work = 1/12
(B + C)'s one day work = 1/16
Now, from the question,
A's 5 days work + B's 7 days work + C's 13 days work = 1
? A's 5 days work + B's 5 days work + B's 2 days work + C's 2 days work + C's 11 days work = 1
(A + B)'s 5 days work + (B + C)'s 2 days work + C's 11 days work = 1
? 5/12 + 2/16 + C's 11 days work = 1
? C's 11 days work = 1 - (5/12 + 2/16) = 11/24
? C's 1 day work = (11/24) x 11 = 1/24
Hence, C can do this work in 24 days.

Let Rohit, Harsh and Sanjeev can type x, y and z pages respectively in 1 h.
Therefore, they together can type 4(x + y + z) pages in 4 h
? 4(x + y + z) = 216
? x + y + z = 54 .....(i)
Also, z - y = y - x
i.e., 2y = x + z ......(ii)

From Eqs. (i) and (ii), we get
3y = 54
? y = 18

From Eq. (ii), x + z = 36 ....(iv)
From Eqs. (iii) and (iv),
we get x = 15 and z = 21

The weight of baggage deliver in 1 min by 1st belt = 3/5 tonne
The weight of baggage deliver in 1 min by 2nd belt = 1/2 tonne
The weight of baggage deliver in 1 min by both belt = 3/5 + 1/2 = 11/10 tonne
So, the two belts delivers 1 tonne in 10/11 min.
Hence, required time to deliver 33 tonne = (10/11) x 33 = 30 min

Since, 50 men can do a job in 50 days.
So, work done by 1 man in a day = 1/(50 x 50)

Also, 80 women can do the job in 50 days.
So, work done by 1 women in 1 day = 1/(50 x 80)

Now, work done by 40 men and 48 women in first 10 days
= (40 x 10)/(50 x 50) + (48 x 10)/(50 x 80)
= 4/25 + 3/25 = 7/25

Now, 5 men and 8 women are removed after 10 days,
So work done by 35 men and 40 women in 10 days = (35 x 10)/(50 x 50) + (40 x 10)/(50 x 80)
= 7/50 + 1/10 = (7 + 5)/50
= 6/25

Again, 5 men and 8 women are removed after 10 days,
So work done by 30 men and 32 women in 10 days = (30 x 10)/(50 x 50) + (32 x 10)/(50 x 80) = 5/25

Now, after every 10 days as the number of men and
women decrease, work done also decreased by 1/25th past.
So, work done after every 10 days upto 50 days = 7/25 + 6/25 + 5/25 + 4/25 + 3/25
= 25/25 = 1

So, it will take 50 days for them to complete the work.

A's 5 day work = 50%
B's 5 day work = 33.33%
C's 2 day work = 16.66% [100 - (50 + 33.33)]
Ratio of contribution of work of A , B and C = 50 : 33.33 : 16.66 = 3 : 2 : 1
A's total share = Rs. 1500
B's total share = Rs. 1000
C's total share = Rs. 500

A's one day's earning = Rs. 300
B's one day's earning = Rs. 200
and C's one day's earning = Rs. 250

Efficiency (Asha : Usha) = 5 : 4
Number of days(Asha : Usha) = 4x : 5x = 4x : 25
? Number of days required by Asha to finish the work alone = 4x
= 4 x 5 = 20.
Now, since Asha and Usha did work together for last 5 days = 5 x 9 = 45%
(since efficiency of Asha = 5% and Usha's efficiency = 4%)
It means Asha completed 55% work alone.
? No. of days taken by Asha to complete 55% work = 55/5 = 11days

Krishna's efficiency = 10%
Mohan's efficiency = 5%
Work done by Krishana and mohan together in 3 days = 15 x 3 = 45%
Now, number of days in which B completed rest (55%) work alone = 55/5 = 11
Total No. of days in which B worked = 3 + 11 = 14
Now No. of days required by B, when A and B both worked together = 100/15 = 6²/₃
? Required difference in No. of days = (11) - (6²/₃)
= 13/3 = 4 1/3 days

Efficiency of Kareena and Krishna = 11.11 + 5.55 = 16.66%
Work done in 3 days = 3 x 16.66 = 50%
Rest work done by Kareena, Krishna and Shahid = 50/50 = 1 day
(Since efficiency of Shahid = 33%)
Thus in ( 3 + 1) days they have completed the work = 4 days.