8 men can complet a piece of work in 20 days. 8 women can do the same work in 32 days. In how many days will 5 men and 8 women together will complete the same work?
All I have is:
Men's one day work = 1/20
Women's one day work = 1/32
Together, 5/20 + 8/32 = 1/2
But 2 days is the wrong answer. The correct answer is 16.
How are these types of questions solved? What is the general trick and mental picture to form?
You forgot the 8 men and 8 women.
A man's work in 1 day: 1/160.
A woman's work in 1 day: 1/256.
Then continue using your method.