selim wrote:
John appointed 25 men to complete a small bridge in 40 days. After 20 days he appointed 15 more workers and the bridge was completed 5 days earlier. If he had not appointed the additional workers by how many days he would have been behind the schedule time ?
A)2 days
B)3 days
C)4 days
D)5 days
E)5/2 Days
25 men*20 days=500 total man days for original crew
40 men*15 days=600 total man days for enhanced crew
500/(500+600)=5/11 of job completed by original crew
let r=daily rate of original crew
r*20=5/11
r=1/44
44-40=4 days behind
C
close
50% (03:55) correct 
