Think of the amount done in 1 hour Together they do 1/7th of the work. The fraction A alone would in 1 hour is 1/x and for B it would be 1/(x+6)
Hence together in 1 hour the fraction they would do would be 1/x+1/(x+6) which therefore =1/7
Thank you, but do you happen to know the answer to the 2nd part of my question?
For the 2nd part I can't see anything wrong with your working. Only the positive answer applies of course.
Yep both +ve and -ve are correct ans for x - its just negative time doesn't make much sense to us.
Originally Posted by biffboy