Aptitude - Time and Work - Discussion

Dear ManikandSenthil,

If we reduce the number of people, then it will take more time 2 do the same work. Like for ex: In above question it is given that 10 women can do 1 work in 7 days, then if we reduce its number, more day it requires 2 do the same work. It is indirectly proportional 2 each other.

It can be done by L.C.M method, but it will be a long method for this particular ques.

L.C.M (7,14)days= 14 units of work,
for women,
in 7 days, 10 women=14 units of work
=>1 women work=14/10 units of work ( in 7 days)
therefore, 1-day work of 1 woman =14/(10*7) = 1/5 units of work

for children,
in 14 days, 10 children=14 units of work
=>1 child work=14/10 units of work ( in 14 days)
therefore, 1-day work of 1 child =14/(10*14) = 1/10 units of work

1 day work of (5 woman+ 10 children) = (1/5)*5 + (1/10)*10 = 2 units of work
But the work to be done is 14 units
thus this work can be done in => 14/2 = 7 days.

Take one women's one day's work = x;

One child's one day's work = y;

10 women can complete the work in 7 days.

So 10x = 1/7.

Similarly 10y = 1/14.

Now take this value in the equation for 5 women and 10 children's work.

5x+10y = 5(1/70)+1/14 = 1/7.

So the total work done in 7 days.

How to use LCM method for this problem please explain?

If ratio is 1:2 then (women * women working days/children)

i.e 10*7/10=7

10 women's one day work =1/7
So 1 women's one day work =1/70
So 5 women's one day work =5*1/70

Similarly,
1 child's one day work = 1/140
and 10 child's one day work = 10/140

10 women's one day work =1/7
So 5 women's one day work=1/14
and 10 child's one day work =1/14

So 5 women's and 10 childrens one day work is

= 1/14 + 1/14
= 2/14
= 1/7

Ans: 7 days.

1 women= 2 childrens

so 5 women+ 10 children=10 women = 7days

Mahesh realy super.

Swamy. Good.