Answer:
10 days
Explanation:
Mr Datu can pay 8 workers for 15 days,
Then at the same rate he can pay 1 worker for the number of days = 15×8
= 120
If he adds number of workers = 4
Then total number of workers = 8 + 4 = 12
With the same rate Mr Datu can pay 12 workers for number of days =

= 10 days
Therefore, Mr Datu can pay 12 workers for 10 days a the same rate.