Aptitude - Time and Work - Discussion

Discussion Forum : Time and Work - Data Sufficiency 2 (Q.No. 1)
Directions to Solve

Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.


1.

In how many days can 10 women finish a work?

I. 

10 men can complete the work in 6 days.

II. 

10 men and 10 women together can complete the work in 3 3 days
7

 III. 

If 10 men work for 3 days and thereafter 10 women replace them, the remaining work in completed in 4 days.

Any two of the three
I and II only
II and III only
I and III only
None of these
Answer: Option
Explanation:

  I. (10 x 6) men can complete the work in 1 day.

      1 man's 1 day's work = 1
60


 II. 10 x 24 men + 10 x 24 women can complete the work in 1 day.
7 7

      240 men's 1 day work + 240 women's 1 day work = 1.
7 7

      240 x 1 + 240 women's 1 day's work = 1.
7 60 7

      240 women's 1 day's work = 1 - 4 = 3
7 7 7

      10 women's 1 day's work = 3 x 7 x 10 = 1
7 240 8

      So, 10 women can finish the work in 8 days.


III. (10 men's work for 3 days) + (10 women's work for 4 days) = 1

      (10 x 3) men's 1 day's work + (10 x 4) women's 1 day's work = 1

      30 men's 1 day's work + 40 women's 1 day's work = 1


      Thus, I and III will give us the answer.

      And, II and III will give us the answer.

      Correct answer is (A).

Discussion:
12 comments Page 1 of 2.

Qwerty said:   3 years ago
How can you derive the answer using statements 2 and 3 alone (without using statement 1)?

Samvid said:   6 years ago
I think the 1st statement must be used. Along with 1st statement, you can use either statement 2 or statement 3 to get the answer. So, in this case, answer should be E.

Vasavi sreenivas said:   6 years ago
Hello everyone.

In the question, they asked 10 women can finish the work in how many days?

1st option it gives only about the men na. How come women days can be obtained?

Purushottam said:   8 years ago
@Amarjee.

20 men, 1 day work = 1/10.
20 men, 3 day work = 3/10.
Remaining work = 1 - 3/10 = 7/10.

Now we take 1 men, 1 day work = 1/60,
Now 5 men return back therefore only 15 men will present.
Now 15 men, 1 day work = 15/200.

Therefore to complete remaining 7/10 work number of days are = (7/10) * (200/15) = 28/3 days.

Amarjeet said:   8 years ago
A contractor estimates that he will employ 20 men to build a tank and complete works in 10 days. After working 3 days together 5 men return back. How many days more will the remaining men take to complete work.

Please help me to answer this.
(2)

Simar said:   8 years ago
@Reshu.

In your answer to solve 2&3, you are using 1 men's 1-day work = 1/60.

I think this is derived from statement 1. Other statements are not mentioning this. So why this used here in solution?
(1)

Anil said:   8 years ago
By using 1st option how we can solve the problem?

Vasu said:   8 years ago
Good explanation.

Reshu said:   9 years ago
1 men's 1 day work = 1/10*6 = 1/60.

(10 men + 10 women)'s 1 day work = 7/24.

1/10*6*10 + 10 women = 7/4.

So 10 women's 1 day work = 7/4-1/6 = 3/24 = 1/8.
(1)

Venkat said:   9 years ago
How 2 & 3 give the answer? Could you please explain me?


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