Quantitative Aptitude: Time and Work Set 5

Time Work Problems tricks Examples IBPS/SBI PO, NIACL, NICl, LIC, Dena Bank PO PGDBF, BOI, Bank of Baroda and other competitive exams

1. A & B can do a work in 60days. B & C can do same work in 30 days. Find in how many days A alone can do the work if C & A can do that work in 40 days?
   A) 240
   B) 360
   C) 120
   D) 480
   E) 180
   
   View Answer

   Option A
   Solution:
   LCM  = 120
   A+B=60 ………120/60 = 2
   B+C=30 …………………… 4
   C+A=40 …………………… 3
   2(A+B+C) = 9
   A+B+C= 9/2
   (A+B+C) – (B+C) = 9/2 – 4= 1/2
   120/1/2= 240 days Ans.
2. A contractor takes a contract to do a work in 30days by 30 men. He found that 10 men were absent in first 10 days. If all men become regular after 10 days then how many more men will be required to complete the work on time?
   A) 35
   B) 5
   C) 25
   D) 7
   E) 6
   
   View Answer

   Option B
   Solution:
   Total work – 30*30        = 900
   1st 10 day work – 20*10 = – 200
   …                                           700
   Now 700 work have to complete in 20 days.
   So – 700/20= 35 men will be require. 30 men are already working so now we need only 5 men.
3. A tap can fill a tank in 18 hours, due to leakage it takes 18hours more to fill the tank. If leakage empty 40ltr water in 1hour then find the capacity of tank?
   A) 720ltr
   B) 480ltr
   C) 1400ltr
   D) 1440ltr
   E) 1320ltr
   
   View Answer

   Option D
   Solution:
   LCM = 36
   A = 18……….. 2
   A+B =1 – 1
   B = 1
   B removes 1 qty in 1 hour so he will empty in 36 hour.
   40*36= 1440ltr.
4. A man & a woman can do a job in 40days. They do work together for 12 days after it with the help of a child they complete the work in 18days. If they get Rs2000 then find how much money will child get?
   A) 600
   B) 900
   C) 500
   D) 1100
   E) 700
   
   View Answer

   Option C
   Solution:
   LCM = 120
   A = 40………..120/40= 3
   B = 60…………………… 2
   .                                    5
   12*5= 60
   Remaining 60 will complete in 6 days. So 60/6 = 10. Now this 10 work will be complete by together .
   Child do 5 work in a day . now the ratio of the total work of all them.
   A ……………..B……………. C
   3*18 ……..2*18…………. 5*6
   54…………. 36……………. 30
   9 : 6 : 5
   Child – 5/20*2000= 500  
5. If a man or 2 women or 3 children can do a work in 33days, then find in how many days will 1 man and 1 woman and 1 child do the work?
   A) 18days
   B) 24days
   C) 20days
   D) 15days
   E) 22 days
   
   View Answer

   Option A
   Solution:
   LCM = 33
   1 man = 33……….. 1
   2 woman = 33………. 1
   3 child = 33………….. 1
   Now we need 1 man + 1 woman+ 1 child
   = 1+ 1/2 + 1/3 = 11/6
   33/11*6= 18 days
6. 40 men undertook to do a work in 50days. After 25days they found only 1/3rd of the work is complete. Find how many more men they need to complete the work on time.
   A) 40
   B) 50
   C) 60
   D) 70
   E) 30
   
   View Answer

   Option A
   Solution:
   40*25/1/3 = (40+x) * 25/2/3
   80 = 40+x
   X= 40 Ans
7. 33 men can do a job In 30 days. If 44 men started the job together and in the end of the day one person left daily.Then what is the minimum number of days required to complete the work?
   A) 21
   B) 42
   C) 45
   D) 44
   E) 36
   
   View Answer

   Option D
   Solution:
   total work = 33*30 = 990
   44 + 43+ 42 = 990
   Now : sum = x/2 (20+(x-1) D)
   A = 44, D = 43-44= -1
   990 = x/2 ( 2*44 +(x-1) -1)
   X= 44 Ans.
8. 5 men can do a piece of work in 2hours, while 7 woman can do in 3 hours or 9 boys do in 4hrs.
   How long would take by 1 man, 1woman, 1boy together to do the work?
   A) 1260/221
   B) 1270/231
   C) 1221/260
   D) 1260/236
   E) 1234/241
   
   View Answer

   Option A
   Solution:
   1 man complete the work in = 2*5= 10 hrs.
   Same 1 woman = 21hrs
   1 boy = 36hrs
   LCM = 1260
   M = 10………1260/10= 126
   W = 21……………………… 60
   B = 36……………………… 35
   .                                     221
   = 1260/221 Ans
9. If 30 men and 14 boys can reap a field in 21 days. In how many days will 20 men and 4 boys will reap it? (When 3 men do as much as work as 5 boys.)
   A) 36 days
   B) 30 days
   C) 42 days
   D) 45 days
   E) 32 days
   
   View Answer

   Option A
   Solution:
   3 men = 5 boys
   M/B = 5/3
   Total work = (30 M + 14B) * 21
   (30*5 + 14*3) *21
   = 4032
   Now: 4032/20*5+4*3= 36 days.
10. A, B, and C can do a work in 18, 30, and 45 days respectively. If they start work with A works the first day, C the second day and B the third and fourth day. If this process continues than find in how many days they will complete the work?
    A) 26 2/3 days
    B) 28 days
    C) 27 2/3 days
    D) 27 days
    E) 27 1/3 days
    
    View Answer

    Option C
    Solution:
    A = 18, B = 30, C = 45
    LCM = 90
    A = 90/18 = 5, B = 3, C = 2
    1st day…………2nd day……………3rd day
    A=5……………..C=2………………….B=3+3
    than
    4 days work = 5 + 2 + 6 = 13
    Make it near total (90)
    4*6…………….. 13*6
    24………………..78
    A -> 1 ……………..5
    B -> 1……………….2
    C -> 1……………….3
    Add
    24+1+1+1=27 days……………..(78+5+2+3) = 88 days
    Now 90-88 = 2 work pending
    B does 3 work in 1 day, so 2 in 2/3. So total 27 2/3 days