17Jul, 2021
Quantitative Aptitude: Time and Work Set 28
  1. A and B can do a work together in 20 days . B and C can do the same work in 15 days C and A also can do the same work in 12 days . In how many days all together can complete the total work and also find the who of them works of the fasted speed.
    20 days, B
    10 days, C
    12 days,A
    18 days, B
    15 days, C
    Option B
    LCM of 20,15 and 12 = 60
    total work =60
    efficiency of A and B together = 60/20=3
    efficiency of B and C together = 60/15 =4
    efficiency of C and A together =60/12=5
    2A+2B+2C =12
    (A+B+C)’s total efficiency = 6
    A,B and C together complete the work =60/6 =10 days .
    A’s efficiency =6-4 =2
    B’s efficiency= 6-5 =1
    C’s efficiency=6-3 = 3
    C works at the fastest speed.

     

  2. A works at half the speed of B and C works at double the speed of B . If they all together can do a work in 40 days. In how many days will A and C complete the same work together ?
    60
    56
    58
    65
    70
    Option B
    Let,
    B’s works speed =2x
    A’s works speed = x
    C’s works speed =4x
    Total work=40*7x=280x
    A & C complete the same work together=280x/5x=56 days

     

  3. M, N & P can do a work individually in 10, 15, and 20 days respectively. If they work together then in how many days the work will be completed ?
    60/13
    60/14
    55/12
    50/11
    5
    Option A
    LCM of 10,15,20=60
    total work=60
    M’s efficiency=60/10=6
    N’s efficiency=60/15=4
    P’s efficiency=60/20=3
    all together can complete the total work=60/13 days

     

  4. X & Y can do a work individually in 20 and 30 days respectively. X starts and works for 10 days. Then he leaves the work and remaining work completed by Y. If they got rs.600, in how much amount did A got ?
    250
    200
    450
    300
    350
    Option D
    LCM of 20 and 30=60
    total work=60
    X works in a day=60/20=3 works
    Y works in a day=60/30=2 works
    X alone work for 10 days= 3*10=30 works
    remaining wrk done by Y=30/2=15 days
    they got rs.600
    A complete half of the work
    so, A will get=600/2= rs.300

     

  5. 102 men can complete a work in 21 days, then how many men would it take to complete 17 days ?
    120
    140
    126
    128
    none of these
    Option C
    102 men can complete a work in 21 days.
    17 days work completed =102*21/17
    =126 men

     

  6. P can don a piece of work in 12 days and Q in 8 days. They begin together, but P goes away 3 days before the work is completed. In how many days the work will be finished ?
    6
    8
    2
    5
    none of these
    Option A
    P can complete in 12 days.
    Q can complete in 8 days.
    Let, the total work =48
    P’s efficiency =48/12 =4
    Q’s efficiency =48/8 =6
    Q worked for 3 days =6*3= 18 work.
    P and Q worked remaining work in days =30/10 =3days.
    Total work will be finished in 6 days.

     

  7. A group of workers worked to finish the work in 25 days . But 10 of the total workers did not come to work and the work is finshed in 35 days. find how many workers worked in the group initially.
    35
    38
    25
    56
    none of these
    Option A
    Let
    the number of workers worked initially is x.
    25*x =(x-10) 35
    25x= 35x-350
    10x=350
    x =35

     

  8. 6 men 4 boys can complete a work in 12 days . A man completes double the work than a boy. In how many days 8 men and 16 boys will complete the work.
    8
    6
    5
    4
    none of these
    Option B
    Let,
    A man can complete 2 work and A boy can complete 1 work.
    1 man=2 boys
    According to questing,
    (6 men + 4 boys) can complete the work =12 days
    6 men + 2 men =8 men + 8men =16 men.
    1 man can do the work =(12*8)days
    (8 men +16 boys) =8 men + 8 men =16 men
    16 men will complete the work = 12*8/16=6 days

     

  9. Avi can complete a work in 30 days. Bibhu is 20% more efficient than Avi and Pintu is 20% less efficient than Avi. In how many days the total work will be completed if they work for together.
    10
    20
    30
    40
    none of these
    Option A
    let,
    efficiency of Avi ,Bibhu and Pintu be 5x, 6x, 4x respectively
    total work =5x*30 = 150x
    Avi, Bibhu, and Pintu will be completed total work= 150x/15x =10 days.

     

  10. P can do work in 25 days and Q is 40% more efficient than P. If Q starts the work and works for 5 days and leaves the work, then in how many days the total work will be finished ?
    25
    26
    24
    23
    none of these
    Option D
    Let,
    efficiency of P and Q = 5x and 7x
    P can do a work in 25 days.
    total work = 25*5x =125x
    Q works for 5 days = 7x*5 =35x
    remaining work done by P=90x/5=18 days
    total work will be completed = 5+18 =23 days.