10 boys and 7 women can do a work in4 days. 3 women and 10 old men can do a same work in 4 days. 1 boy 1 woman and 1 old man can do a wok in how many days
Answers
Answer:
A can do a work alone in 4 days. And same work B can complete in 5 days. And with the help of C they can do the work in 2 days.
Let me tell you shortcut for these types of problems :
We dont know how much work is there to do. So lets find out that first..
Just take the LCM of 4,5 and 2 ….
You know from where 4,5 and 2 came. Its the time that A ,B and A+B+C took to complete the work.
LCM of 4,5 and 2 is 20.
So total work is 20. A took 4 days to complete 20 work alone i.e. it did 5 work per day.(efficiencyis 5 of A). B took 5 days to complete 20 work alone,with the efficiency of 4 per day.
Now the deciding factor A+B+C can do the work in 2 days means 10 work per day. A can do 5 work per day ,B can do 4 work per day.they both can do 9 work per day. As we know that
A+B+C can do 10 work a day.
And
A+B can do 9 work a day.
As A and B can do 9 work then what is left for C !
Only 1.
If C work with 1 work per day efficiency then how many days it will take to complete 20 work?
Yes you are right .
20 days.
Answer: