Aptitude - Time and Work - Discussion

Discussion Forum : Time and Work - General Questions (Q.No. 12)
12.
4 men and 6 women can complete a work in 8 days, while 3 men and 7 women can complete it in 10 days. In how many days will 10 women complete it?
35
40
45
50
Answer: Option
Explanation:

Let 1 man's 1 day's work = x and 1 woman's 1 day's work = y.

Then, 4x + 6y = 1 and 3x + 7y = 1 .
8 10

Solving the two equations, we get: x = 11 , y = 1
400 400

1 woman's 1 day's work = 1 .
400

10 women's 1 day's work = 1 x 10 = 1 .
400 40

Hence, 10 women will complete the work in 40 days.

Discussion:
106 comments Page 2 of 11.

Khyati mehta said:   4 years ago
Men=m, Women = w.

4m+6w = 1/8 so 32m + 48w = 1 ---> (1)
3m+7w = 1/10 so 30m + 70w = 1 ---> (2)

Now find the relation between m and w by equating 1 and 2.
We get m=11w.
Now put it in equation 1 we get;
4m+6w.
4*(11w)+6w.
50w complete work in 8 days.
10w complete work in (8*50)/10 = 40 days.
(7)

Varshini said:   5 years ago
@All.

Please let me know.

How come x=11/400 and y=1/400?

Anybody explain.
(4)

Jigme said:   5 years ago
Hi,

Could you please show me how did you compute to get x=11/400 & y = 1/400?

Nayana said:   5 years ago
@All. The Shortcut method:

4m 6w =8days -> 1
3m 7w = 10day -> 2.

(4m+6w)8 = (3m+7w)10
32m+48w = 30m +70w
32m-30m = 70w-48w.

2m = 22w
1m = 11w ---> (3).

Substitute (3) in (1) or(2)

Eq(2)Converting men to women
(3m+7w)10.
((3*11w)+7w)10 = 10x.
40*10 = 10x.
x = 400/10.
x = 40.
Hope it is helpful.
(18)

Priya said:   6 years ago
I cannot understand this equation.
4x+6y=1/8.
3x+7y=1/10.

Please explain.

Harpreet said:   6 years ago
4 x+6y = 1/8 (I)
3x+7y=1/10.

32x+48y=1....(1)
30x+70y=1....(2)

2x-22y=0
X=11y

4*11y + 6y = 1/8
10y = 1/40.

Kermiki Bang said:   6 years ago
Then, 4x + 6y =1/8 and 3x + 7y =1/10.

Solving the two equations,

We get: x = 11/400, y =1/400

Can someone help me with this?

Eno said:   6 years ago
Please, we have been using 1/n for 1 day's work. How come we are now saying that let 1 man's day be x and 4 days be 4x?

Or are we trying to say we have to cram how each examples are used and not to go by the 1/n always?

Santosh K said:   6 years ago
4M+6W=8.
3M+7W=10.
10W=?.

1day work of 4M+6W=1/8,
3M+7W=1/10.

8(4M+6W) = 1.
10(3M+7W) = 1.

Now equate both equations:

32M + 48W = 30M + 70W.
32M - 30M = 70W - 48W.
2M = 22W.
1M = 11W--->3.

Substitute equation 3 in 1.

4 * 11W + 6W = 1/8.
44W + 6W = 1/8,
50W = 1/8; 10W=?
10 * 1/8 * 50 = 1/40.

Therefore 10 women can complete the work in 40days.

Sasi Lawandi said:   6 years ago
How to get 1 woman's day work = 1/400.

Can you please explain it clearly? Can't understand about it.


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