Question

A can do a piece of work in 12 days, while B can do it in 20 days. a worke at it for 9 days. in how many days can B finish the remaining work?

Answer 1

Ans) 5 days
   By Ratio and Proportion:
 
12:9::20:x
thus, 12x=9*20
x= 15
Thus, B finishes in 15 days