Aptitude  Time and Work
Exercise : Time and Work  General Questions
 Time and Work  Formulas
 Time and Work  General Questions
 Time and Work  Data Sufficiency 1
 Time and Work  Data Sufficiency 2
 Time and Work  Data Sufficiency 3
26.
A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in :
Answer: Option
Explanation:
(A + B + C)'s 1 day's work =  1  ; 
6 
(A + B)'s 1 day's work =  1  ; 
8 
(B + C)'s 1 day's work =  1  . 
12 
(A + C)'s 1 day's work 







So, A and C together will do the work in 8 days.
27.
A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in:
Answer: Option
Explanation:
(B + C)'s 1 day's work =  1  +  1  =  7  .  
9  12  36 
Work done by B and C in 3 days =  7  x 3  =  7  .  
36  12 
Remaining work =  1   7  =  5  .  
12  12 
Now,  1  work is done by A in 1 day. 
24 
So,  5  work is done by A in  24 x  5  = 10 days.  
12  12 
28.
X can do a piece of work in 40 days. He works at it for 8 days and then Y finished it in 16 days. How long will they together take to complete the work?
Answer: Option
Explanation:
Work done by X in 8 days =  1  x 8  =  1  .  
40  5 
Remaining work =  1   1  =  4  .  
5  5 
Now,  4  work is done by Y in 16 days. 
5 
Whole work will be done by Y in  16 x  5  = 20 days.  
4 
X's 1 day's work =  1  , Y's 1 day's work =  1  . 
40  20 
(X + Y)'s 1 day's work =  1  +  1  =  3  .  
40  20  40 
Hence, X and Y will together complete the work in  40  = 13  1  days.  
3  3 
29.
A and B can do a job together in 7 days. A is 1 times as efficient as B. The same job can be done by A alone in :
Answer: Option
Explanation:
(A's 1 day's work) : (B's 1 day's work) =  7  : 1 = 7 : 4. 
4 
Let A's and B's 1 day's work be 7x and 4x respectively.
Then, 7x + 4x =  1  11x =  1  x =  1  . 
7  7  77 
A's 1 day's work =  1  x 7  =  1  .  
77  11 
30.
A and B together can do a piece of work in 30 days. A having worked for 16 days, B finishes the remaining work alone in 44 days. In how many days shall B finish the whole work alone?
Answer: Option
Explanation:
Let A's 1 day's work = x and B's 1 day's work = y.
Then, x + y =  1  and 16x + 44y = 1. 
30 
Solving these two equations, we get: x =  1  and y =  1 
60  60 
B's 1 day's work =  1  . 
60 
Hence, B alone shall finish the whole work in 60 days.
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