Today I am going to share techniques to solve Time and Work question. I have already shared a technique for this chapter here.
Question - A can do a piece of work in 10 days and B can do the same work in 15 days. How long will they take to do the work together.Answer -
This topic is based on two main concepts:
- ONE DAY WORK: Unitary Method
- TOTAL WORK
Question - A can do a piece of work in 10 days and B can do the same work in 15 days. How long will they take to do the work together.Answer -
A =10 days
B = 15 days
A+B = ? days
To answer we can apply two methods.
According to the first method
If A can do a piece of work in 10 days
A’s one day work = 1/10
Similarly B’s one day work = 1/15
So this method says that
To do 1/6 work (A+B) take = 1 day
To do 1 work (A+B) take = 1/ (1/6) = 1 x6/1 = 6 days
Based on this method , the shortcut would be:
SECOND METHOD :
A = 10 days
B = 15 days
Total work = 30 units
WHY 30 units ?
Remember the LCM of 10 and 15 is 30.
A does 1 work in 10 days so in one A will do = 30/10 = 3 units
B does 1 work in 15 days so in 1 day B will do = 30/15 = 2 units
So together ( A+B) complete = 3+2 = 5 units in one day
Now which method to be applied, depends upon the kind of
questions asked and your comfort level.
Question - A can do a piece of work in 10 days. A and B together take 6 days to complete the work. How long will B take to complete the work?This entry passed through the Full-Text RSS service - if this is your content and you're reading it on someone else's site, please read the FAQ at http://ift.tt/jcXqJW.
No comments:
Post a Comment