Question

please solve this question by full method question 11

Answer 1

Since 12 men can reap the field in 7 days . One man can reap (1/12*7) = (1/84)th field a day.

Since 18 women can reap the field in 7 days . One women can reap (1/18*7) = (1/126)th field a day .

Now we have 4 men and 8 women working . So, the total number of days taken would be the reciprocal of:

4*(1/84)+8*(1/126) = 7/63 = 1/9

Therefore 4 men and 8 women reap the same field in 9 days

Answer 2

It's Pretty simple If you can understand What I am going to do here,

Let a man can complete the single work in x days,
=> In 1 day he will do 1/x work,

Let a woman can complete the single work in y days,
=> In 1 day she will do 1/y work ,

Now Given that, 12 men or 18 women can complete the work in 7 days,
=> 12(1/x)*7 = 1
=> 84*1/x = 1
=> x = 84, Which means, A man can complete single work in 84 days, Here 1 represents the unit of work,

Now 18(1/y)*7 = 1,
=> y = 126,Which means, A women can complete single work in 126 days,

Now together in how many days 4 men and 8 women can complete is the question,

Let No. of days taken be a ,
=> a*((4/84) + (8/126)) = 1
=> a*((12/252) + (16/252)) = 1,
=> a = 252/28,
=> a = 9

Now here is the answer, 4 men and 8 women will take 9 days to complete the work !

Hope you understand, Have a great day !