Q: 56 (IAS/2007)

A and B can complete work together in 5 days. If A works at twice his speed and B at half of his speed, this work can be finished in 4 days. How many days would it take for A alone to complete the job?
question_subject: 
Maths
question_year: 
2007
question_exam: 
IAS
question_sub_subject: 
Mathematics
question_topic: 
Mathematics
stats: 
0,120,112,120,64,32,16