# Aptitude - Time and Work - Discussion

Discussion Forum : Time and Work - General Questions (Q.No. 27)

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 |

Discussion:

17 comments Page 1 of 2.
Anonymous said:
3 years ago

It is very simple,

Work done By B and C in first 3 days = 7/12,

Work Done by A in 1 day = 1/24,

Hence, 7/12 + n(1/24) = 1 where n represents number of days.

On solving, n = 24-14 = 10 days.

Work done By B and C in first 3 days = 7/12,

Work Done by A in 1 day = 1/24,

Hence, 7/12 + n(1/24) = 1 where n represents number of days.

On solving, n = 24-14 = 10 days.

(1)

Student said:
3 years ago

Yes, you are correct Thanks @Shilpi.

Himanshu said:
3 years ago

A = 24.

B = 9.

C = 12.

Take LCM of 24, 9, 12=72.

Now, we will find how much work done in a day,

A = 72/24 = 3per day.

B = 72/9 = 8per day.

C = 72/12 = 6per day.

B+C = 14, from above.

B and Cwork for 3 days, so,

3*14 = 42.

Total work 72.

42 work is already done by B and C.

Remaining work 72-42 = 30.

Now,

A will complete 30 work,so

A is doing 3 work in a day, from above

So 30/3=10 days

B = 9.

C = 12.

Take LCM of 24, 9, 12=72.

Now, we will find how much work done in a day,

A = 72/24 = 3per day.

B = 72/9 = 8per day.

C = 72/12 = 6per day.

B+C = 14, from above.

B and Cwork for 3 days, so,

3*14 = 42.

Total work 72.

42 work is already done by B and C.

Remaining work 72-42 = 30.

Now,

A will complete 30 work,so

A is doing 3 work in a day, from above

So 30/3=10 days

(2)

Arun said:
6 years ago

5 women can do a work in 36 days. If ratio b/w the capacity of men and women is 1:3 then find how many day it will take 5 men to complete the same work? Please solve this.

Banodai said:
6 years ago

A can do a work = 1/24.

B can do a work = 1/9.

C can do a work = 1/12.

Whole work have done,

T/24+3/9+3/12 = 1.

T/24+1/3+1/4 = 1.

T/24+7/12 = 1.

T/24+14/24 = 1.

T+14/24 = 1.

T+14 = 24.

T = 24-14.

T = 10 days

Answer : 10 days.

B can do a work = 1/9.

C can do a work = 1/12.

Whole work have done,

T/24+3/9+3/12 = 1.

T/24+1/3+1/4 = 1.

T/24+7/12 = 1.

T/24+14/24 = 1.

T+14/24 = 1.

T+14 = 24.

T = 24-14.

T = 10 days

Answer : 10 days.

(1)

Mithun said:
7 years ago

7 * 3/36 + x/24 =1

Because:

(B+C) worked for 3 days + followed by A =1 [total work].

Assume x number of days.

Because:

(B+C) worked for 3 days + followed by A =1 [total work].

Assume x number of days.

(1)

Shilpi said:
7 years ago

A-24days

B-9days

C-12days.

Days LCM 72.

72/24 = 3.

72/9 = 8.

72/12 = 6.

3, 8, 6are efficiency of ABC.

B + C (do work 3 days) = 8 + 6 = 14 * 3 = 42 total work = 72 - 42 = 30. So A work alone30/3 = 10days.

B-9days

C-12days.

Days LCM 72.

72/24 = 3.

72/9 = 8.

72/12 = 6.

3, 8, 6are efficiency of ABC.

B + C (do work 3 days) = 8 + 6 = 14 * 3 = 42 total work = 72 - 42 = 30. So A work alone30/3 = 10days.

(2)

Sandra said:
8 years ago

Can anyone explain the last step of 24 * 5/12?

(1)

Innareddy Chilakala said:
8 years ago

A = 24.

B = 9.

C = 12.

B & C started after 3 days they leave (The do only 3 days).

Total work = X.

A joined after 3 days X-3 (He finished the work).

= X-3/24 + 3/9 + 3/12 = 1.

To solve this we get X = 13.

A = X-3.

= 13-3.

= 10 days.

B = 9.

C = 12.

B & C started after 3 days they leave (The do only 3 days).

Total work = X.

A joined after 3 days X-3 (He finished the work).

= X-3/24 + 3/9 + 3/12 = 1.

To solve this we get X = 13.

A = X-3.

= 13-3.

= 10 days.

Kavya said:
9 years ago

Total work equal to 1.

But B, C are left after 3 days we have to find remaining work of A?

A Consider as X.

Equation can be written as X/24+3/9+3/12 = 1.

By solving (3X+24+18) /72 = 1.

3X = 72-42.

X = 10.

But B, C are left after 3 days we have to find remaining work of A?

A Consider as X.

Equation can be written as X/24+3/9+3/12 = 1.

By solving (3X+24+18) /72 = 1.

3X = 72-42.

X = 10.

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