If 3 men or 4 women take 30 days to do a certain work, then how long will 9 men or 8 women take to complete the same work?
Answers
Answer:
3 Men or 4 Women can finish the work in 43 days, therefore, in one day 3 men or 4 women can finish 1/43 amount of the total work. Therefore, a man can finish 1/43 * 1/3 amount of work in a day and a woman can finish 1/43 * 1/4 amount of work in a day.
When 7 men and 5 women are working together, amount of work done in a day = 7 * (1/ 43) * (1/3) + 5 * (1/ 43) * (1/4) amount of work in a day.
= (1/43)* (7/3 + 5/4)
= (1/43)* (43 / 12)
= 1/12
So 7 men and 5 women finish 1/12 of the work in day. Hence, 7 men and 5 women can finish the entire work in 12 days.
This method can be used in solving similar kinds of problems in future regardless the way problem is presented ( a big tap fills the tank in x hours and a small tank in y hours. How many hours would it take for both of them to fill it together) . All of them use the same concept.
Find the amount of work done per unit time and calculate the overall time required in different conditions.
Hope this helps :)
Answer:
I think 8or 9 women complete this work in 15 days