1. ## Problem

Could someone help me with this problem? I'm totally lost.

An experienced typist can type a brief in 6 hours. Her assistant can type the same brief in 9 hours. If they both work together for 3 hours and then the experienced typist work alone, how many hours will it take her to finish the job?

Thanks,

2. Originally Posted by lila
Could someone help me with this problem? I'm totally lost.

An experienced typist can type a brief in 6 hours. Her assistant can type the same brief in 9 hours. If they both work together for 3 hours and then the experienced typist work alone, how many hours will it take her to finish the job?

Thanks,
Expereienced typist types 1/6th work in one hour
her assistant types 1/9th of the work in one hour
so combined work done in 3 hours $=\frac{1}{6}*3+\frac{1}{9}*3$
hence work left $=1-\frac{5}{6}$ =1/6th of total work
hence it takes one more hour by experienced typist...

3. thank you so much ADARSH.