Some Category of workers can complete a decided project in 20 days. However, due to some unpredicted situation, 5 workers were absent. That’s why, the project got detained by 5 days. If each worker does the similar amount of work and all workers are equally efficient, then how many workers were initially allocated to the project?

Let's we consider that the number of workers initially allocated to the project is 'a'. In one day, 'a' workers can complete 1/20th of the project. Then, due to unpredicted situation there will absence of 5 workers, the effective number of workers working on the project is (a - 5). Since the project got detained by 5 days, the entire number of days taken to complete the project is 20 + 5 = 25. Therefore, we can set up the equation to solve for 'a': (a- 5) x 25 = a x 20 25a - 125 = 20a 25a – 20a = 125 5a = 125 a = 125 / 5 a = 25 Therefore, the initial number of workers allocated to the project is 25.