Time and Work


  1. A certain number of men can complete a job in 30 days. If there were 5 men more, it could be completed in 10 days less. How many men were in the beginning?









  1. View Hint View Answer Discuss in Forum

    Let initially the number of men be x.
    ⇒ According to question,
    M1D1 W2 = M2 D2 W1
    x × 30 = (x + 5) × (30 – 10)
    x × 30 = 20x + 100
    30x – 20x = 100
    10x = 100
    x = 10
    Aliter : Using Rule 23,
    Here, D = 30, a = 5, d = 10
    Required number

    =
    a(D - d)
    d

    =
    5(30 - 10)
    = 10
    10

    Correct Option: A

    Let initially the number of men be x.
    ⇒ According to question,
    M1D1 W2 = M2 D2 W1
    x × 30 = (x + 5) × (30 – 10)
    x × 30 = 20x + 100
    30x – 20x = 100
    10x = 100
    x = 10
    Aliter : Using Rule 23,
    Here, D = 30, a = 5, d = 10
    Required number

    =
    a(D - d)
    d

    =
    5(30 - 10)
    = 10
    10


  1. A skilled, a half skilled and an unskilled labourer work for 7, 8 and 10 days respectively and they together get 369 for their work. If the ratio of their each day’s work is
    1
    :
    1
    :
    1
    346

    then how much does the trained labourer get (in rupees) ?









  1. View Hint View Answer Discuss in Forum

    Using Rule 25,
    Skilled : half skilled : unskilled

    =
    1
    :
    1
    :
    1
    346

    =
    1
    × 12:
    1
    × 12:
    1
    × 12= 4 : 3 : 2
    346

    Share of the trained labourer
    =
    28
    × 369
    (7 × 4 + 8 × 3 + 2 × 10)

    =
    28
    × 369
    (28 + 24 + 20)

    =
    28
    × 369 = ₹ 143.50
    72

    Correct Option: D

    Using Rule 25,
    Skilled : half skilled : unskilled

    =
    1
    :
    1
    :
    1
    346

    =
    1
    × 12:
    1
    × 12:
    1
    × 12= 4 : 3 : 2
    346

    Share of the trained labourer
    =
    28
    × 369
    (7 × 4 + 8 × 3 + 2 × 10)

    =
    28
    × 369
    (28 + 24 + 20)

    =
    28
    × 369 = ₹ 143.50
    72



  1. A, B and C are employed to do a piece of work for ₹ 575. A and C are supposed to finish 19/23 of the work together. Amount shall be paid to B is









  1. View Hint View Answer Discuss in Forum

    Work done by B

    = 1 -
    19
    =
    23 - 19
    =
    4
    232323

    ∴ (A + C) : B =
    19
    :
    4
    = 19 : 4
    2323

    ∴ Sum of ratios = 19 + 4 = 23
    ∴ B’s share
    =
    4
    × 575 = ₹ 100
    23

    Correct Option: B

    Work done by B

    = 1 -
    19
    =
    23 - 19
    =
    4
    232323

    ∴ (A + C) : B =
    19
    :
    4
    = 19 : 4
    2323

    ∴ Sum of ratios = 19 + 4 = 23
    ∴ B’s share
    =
    4
    × 575 = ₹ 100
    23


  1. If a man earns ₹ 2000 for his first 50 hours of work in a week and is then paid one and a half times his regular hourly rate for any additional hours, then the hours must he work to make ₹ 2300 in a week is









  1. View Hint View Answer Discuss in Forum

    Earning in the first one hour

    =
    2000
    = Rs. 40
    50

    Earnings for additional 5 hours
    = 40 ×
    3
    × 5 = Rs. 300
    2

    Correct Option: D

    Earning in the first one hour

    =
    2000
    = Rs. 40
    50

    Earnings for additional 5 hours
    = 40 ×
    3
    × 5 = Rs. 300
    2



  1. 2 men and 1 woman can complete a piece of work in 14 days while 4 women and 2 men can do the same work in 8 days. If a man gets Rs. 180 per day, then a woman will get per day









  1. View Hint View Answer Discuss in Forum

    (2 men + 1 woman)’s 14 days’ work ≡ (4 women + 2 men)’s 8 days’ work
    ⇒ 28 men + 14 women ≡ 32 women + 16 men
    ⇒ (28 – 16) = 12 men ≡ (32 – 14) = 18 women
    ⇒ 2 men ≡ 3 women

    ∴ 1 woman ≡
    2
    man
    3

    ∵ Wages per day of 1 man = Rs. 180
    ∴ Wages per day of 1 woman
    =
    2
    × 180 = Rs. 120
    3

    Correct Option: C

    (2 men + 1 woman)’s 14 days’ work ≡ (4 women + 2 men)’s 8 days’ work
    ⇒ 28 men + 14 women ≡ 32 women + 16 men
    ⇒ (28 – 16) = 12 men ≡ (32 – 14) = 18 women
    ⇒ 2 men ≡ 3 women

    ∴ 1 woman ≡
    2
    man
    3

    ∵ Wages per day of 1 man = Rs. 180
    ∴ Wages per day of 1 woman
    =
    2
    × 180 = Rs. 120
    3